Since its launch in 1999, the Far Ultraviolet Spectroscopic Explorer (FUSE) has had a profound impact on many areas of astrophysics. Although the prime scientific instrument continues to perform well, numerous hardware failures on the attitude control system, particularly those of gyroscopes and reaction wheels, have made science operations a challenge. As each new obstacle has appeared, it has been overcome, although sometimes with changes in sky coverage capability or modifications to pointing performance. The CalFUSE data pipeline has also undergone major changes to correct for a variety of instrumental effects, and to prepare for the final archiving of the data. We describe the current state of the FUSE satellite and the challenges of operating it with only one reaction wheel and discuss the current performance of the mission and the quality of the science data.

The AGILE Mission will explore the gamma-ray Universe with a very innovative instrument combining for the first time a gamma-ray imager (sensitive in the range 30 MeV - 50 GeV) and a hard X-ray imager (sensitive in the range 15-45 keV). An optimal angular resolution and a large field of view are obtained by the use of state-of-the-art Silicon detectors integrated in a very compact instrument. AGILE will be operational at the beginning of 2007 and it will provide crucial data for the study of Active Galactic Nuclei, Gamma-Ray Bursts, unidentified gamma-ray sources, Galactic compact objects, supernova remnants, TeV sources, and fundamental physics by microsecond timing.

The Swift gamma-ray burst explorer was launched on Nov. 20, 2004 from Cape Canaveral, Florida. The first instrument onboard became fully operational less than a month later. Since that time the Burst Alert Telescope (BAT) on Swift has detected more than one hundred gamma-ray bursts (GRBs), most of which have also been observed within two minutes by the Swift narrow-field instruments: the X-Ray Telescope (XRT) and the Ultra- Violet and Optical Telescope (UVOT). Swift trigger notices are distributed worldwide within seconds of the trigger through the Gamma-ray burst Coordinates Network (GCN) and a substantial fraction of GRBs have been followed up by ground and space-based telescopes, ranging in wavelength from radio to TeV. Results have included the first rapid localization of a short GRB and further validation of the theory that short and long bursts have different origins; detailed observations of the power-law decay of burst afterglows leading to an improved understanding of the fireball and afterglow models; and detection of the most distant GRB ever found. Swift is also a sensitive X-ray observatory with capabilities to monitor galactic and extragalactic transients on a daily basis, carry out the first all-sky hard X-ray survey since HEAO-1, and study in detail the spectra of X-ray transients.

Suzaku satellite, the Japan-US collaborative mission, was successfully launched on July 10, 2006. It is equipped with 5 soft X-ray telescopes (XRT), one micro-calorimeter (XRS), 4 CCD cameras (XIS), and one hard X-ray detector (HXD). Though XRS is not operational, XIS and HXD provide us with new views of thermal and non-thermal phenomena. Better efficiency and energy resolution of CCD allow us to investigate emission lines from C and O, as well as Fe-K lines. Objectives are planetary nebula, supernova remnants, Galactic center and cluster of galaxies. The status and origin of the plasmas are well examined from the line energies, line ratios, and line broadening. Another area, Suzaku satellite has advantages is broadband spectroscopy with better sensitivity. Targets are X-ray binaries, active galactic nuclei, and cluster of galaxies. Non-thermal components are well determined by the broad band spectra and their variability. Broad iron lines are well confirmed with accurate determination of underlying continuum components. After the performance verification phase with 70 targets, the first term of general observer program (AO-1) has been started from April 1. AO-2 proposals are due December 1, 2006. It is also announce that a Suzaku Symposium will be held on December 4-8, Kyoto, Japan.

Since hot 100,000-1,000,000K gas in stars radiates predominantly at EUV and soft X-ray wavelengths, observations in these bands provide important diagnostics of the physical conditions in hot photospheres, stellar coronae and stellar winds. However, such studies are only able to examine the bulk of material, without being able to separate out the several gas components present. Radial velocity diagnostics have been used frequently in the UV and visible bands to distinguish different emission or absorption components in stellar spectra. Now, developments in grating and instrument technology provide a first opportunity to extend this technique into the EUV. Based on capabilities of the improved JPEX spectrometer (reported elsewhere in this volume), this paper reports on the key science that might be carried out with such an instrument; both as a sounding rocket payload and longer duration mission.

Progress of modern astrophysics requires the access to the electromagnetic spectrum in the broadest energy range. The ultraviolet is a fundamental energy domain; warm plasmas at temperatures of 3,000-300,000 K radiate in this range, also the electronic transitions of the most abundant molecules in the Universe are in the UV. Moreover, the UV radiation field is a powerful astrochemical and photoionizing agent. Some of the most relevant problems in modern astrophysical research are related with the properties and abundance of this warm plasma in the Universe, e.g. the chemical enrichment of the Universe, the formation of the galaxies or the contribution of the InterGalactic Medium (IGM) to the total mass of the Universe. Also, this plasma is the primary tracer of some very important processes for the generation of life in our planet like the onset and stabilization of the Solar dynamo or the acceleration of organic chemistry processes in young planetary disks. This contribution represents a brief accounting of the BIG science to be carried out if new UV instrumentation becomes, eventually, available.

Micro-X is a proposed sounding rocket experiment that will combine a transition-edge-sensor X-ray-microcalorimeter array with a conical imaging mirror to obtain high-spectral-resolution images of extended and point X-ray sources. We describe the payload and the science targeted by this mission including the discussion of three possible Micro- X targets: the Puppis A supernova remnant, the Virgo Cluster, and Circinus X-1. For example, a Micro-X observation of the bright eastern knot of Puppis A will obtain a line-dominated spectrum with 90,000 counts collected in 300 seconds at 2 eV resolution across the 0.3-2.5 keV band. Micro-X will utilize plama diagnostics to determine the thermodynamic and ionization state of the plasma, to search for line shifts and broadening associated with dynamical processes, and seek evidence of ejecta enhancement. For clusters of galaxies, Micro-X can uniquely study turbulence and the temperature distribution function. For binaries, Micro-X's high resolution spectra will separate the different processes contributing to the Fe K lines at 6 keV and give a clear view of the geometry of the gas flows and circumstellar gas.

Non-thermal phenomena is now-a-days recognized as an important half of the energetics of the Universe. Hard X-ray emission from energetic particles is the most important clue to investigate the non-thermal phenomena. Hard X-ray imaging telescopes are known to improve the sensitivity of hard X-ray observations dramatically. Since hard X-rays above 25 keV can be observed at the altitude of 40 km, we are performing hard X-ray imaging balloon experiments as the path finders of future satellite missions of hard X-ray imaging. Major fields we are looking into are non-thermal components from SNR and Cluster of galaxies and the power law components from AGN even with thick column. The former are related to acceleration mechanisms of high energy particles responsible for hard X-ray power law components. The latter is the complete search of emission from massive blackholes which contribute most to the cosmic X-ray background. Our current balloon programs are InFOCμS experiment and SUMIT project. NeXT is the hard X-ray imaging mission proposed as the next Japanese X-ray mission.

High resolution and signal to noise spectral observations of AGN outflows in the UV demonstrate the need for using covering factor models in calculating absorber column densities. We study the best X-ray data set of an AGN outflow, the Chandra 900 kilosecond observation of NGC 3783, for similar effects in the strongly saturated line series of NeX and OVII. Velocity-dependent covering factor generates much better fits to the OVII He-like series than full covering with the same amount of column. There is also evidence for covering factor in strong L-shell Fe lines. With the low resolution of the HETGS relative to absorption troughs, full covering and partial covering yield similar fits to the NeX Lyman series. Still, both models produce NeX column densities 5 times higher than previous analyses. We generate synthetic data for the future Con-X mission and compare to the Chandra 900 ks data. We calculate the necessary resolution and effective area to correctly identify covering factor models.

The NeXT (New X-ray Telescope/Non-thermal Energy eXploration Telescope) mission has been proposed in Japan as a successor to the Suzaku mission. NeXT has two major mission goals, one is to study the high-energy non-thermal Universe by utilizing the technology of focusing optics above 10 keV, and second is to recover science which should have been achieved by the XRS of Suzaku. The mission will feature multiple instruments covering the bandpass ranging from 0.5 keV to 300 keV. NeXT will carry two hard X-ray telescopes for a hard X-ray imager, two soft X-ray telescopes, one is for a soft X-ray spectrometer, and the other is for a soft X-ray imager. In the soft gamma-ray band up to ~ 300 keV, a narrow field-of-view Compton gamma-ray telescope utilizing several tens of layers of thin Si or CdTe detector will provide high resolution spectra with much higher sensitivity than present instruments, along with polarization information. The continuum sensitivity of the mission will reach several x 10^-8 photons/s/keV/cm² in the hard X-ray region and a few x 10^-7 photons/s/keV/cm² in the soft γ-ray region.

Simbol-X is a hard X-ray mission, operating in the ~ 0.5-80 keV range, proposed as a collaboration between the French and Italian space agencies with participation of German laboratories for a launch in 2013. Relying on two spacecraft in a formation flying configuration, Simbol-X uses for the first time a 20-30 m focal length X-ray mirror to focus X-rays with energy above 10 keV, resulting in over two orders of magnitude improvement in angular resolution and sensitivity in the hard X-ray range with respect to non-focusing techniques. The Simbol-X revolutionary instrumental capabilities will allow us to elucidate outstanding questions in high energy astrophysics such as those related to black-holes accretion physics and census, and to particle acceleration mechanisms, which are the prime science objectives of the mission. After having undergone a thorough assessment study performed by CNES in the context of a selection of a formation flight scientific mission, Simbol-X has been selected for a phase A study to be jointly conducted by CNES and ASI. The mission science objectives, the current status of the instrumentation and mission design are presented in this paper.

We present our proposal for a small X-ray mission DIOS (Diffuse Intergalactic Oxygen Surveyor), consisting of a 4-stage X-ray telescope and an array of TES microcalorimeters, cooled with mechanical coolers, with a total weight of about 400 kg. The mission will perform survey observations of warm-hot intergalactic medium using OVII and OVIII emission lines, with the energy coverage up to 1.5 keV. The wide field of view of about 50' diameter, superior energy resolution close to 2 eV FWHM, and very low background will together enable us a wide range of science for diffuse X-ray sources. We briefly describe the design of the satellite, performance of the subsystems and the expected results.

The most recent observations of the cosmic microwave background (e.g., WMAP) show that baryons contribute about 4% to the total density of the Universe. However at redshift less than or equal to 1, about half of these baryons have not yet been observed. Cosmological simulations predict that these "missing" baryons should be distributed in filaments, have temperatures of 10⁵ to 10⁷ K and overdensities of a few to hundred times the average baryon density, forming the so-called Warm-Hot Intergalactic Medium (WHIM). There is increasing evidence from Chandra and XMM-Newton that the WHIM may indeed exist. However it is clear that to map the morphology of the WHIM and to measure its physical conditions, a completely different class of instruments is required. Measuring the WHIM in emission in the soft X-ray band is a promising option. To detect the relatively weak, extended emission of the WHIM, the instrument should have a large grasp (collecting area times field of view), and an energy resolving power of about 500 at 1 keV is required to separate the emission of these large scale filaments from foreground emission. We discuss a design that includes X-ray mirrors in combination with a large 2D cryogenic detector, which will allow us to map a significant fraction of this gas. Such detector and its read-out based on Frequency Domain Multiplexing, are currently under development at SRON. It seems feasible to build an array of 24 x 24 pixels of TES microcalorimeters with good energy resolution (few eV). This detector will be combined with a mirror design which is based on 2 and 4 reflections and gives a large area (> 500 cm²) over a relatively large field of view. A preliminary study of the mission concept indicates that this can be implemented in a relatively small satellite (total weight 650 kg). While the main goal of this satellite will be to map and study the physical properties of the missing baryons, the instrument's large area and large field of view will also result in major progress in related fields.

There is a growing consensus that a substantial fraction of the matter in the universe, especially what we think of as normal baryonic matter, exists in a tenuous, hot filamentary intergalactic medium often referred to as the Cosmic Web. Improving our understanding of the web has been a high priority scientific goal in NASA's planning and roadmapping activities. NASA recently supported an Origins Probe study that explored the observable phenomenology of the web in detail and developed concepts for the instrumentation and mission. The Baryonic Structure Probe operates in the ultraviolet spectral region, using primarily O VI (λλ 1032, 1038 angstrom) and HI Ly α (λ 1216 angstrom) as tracers of the web. A productive investigation requires both moderate resolution (R = λ/Δλ ~ 30000) absorption line spectroscopy using faint background quasars as continuum sources, and imaging of the diffuse filaments in emission lines of the same ions. Spectroscopic sensitivity to quasars as faint as V ~ 19 will probe a large number of sight lines to derive physical diagnostics over the redshift range 0 < z < 1. Spectral imaging with a wide field of view and sensitivity to a redshift range 0 < z < 0.3 will map the filaments in a large volume of the universe after the web had evolved to near its modern structure. This paper summarizes the scientific goals, identifies the measurement requirements derived from them, and describes the instrument concepts and overall mission architecture developed by the BSP study team.

SMESE (SMall Explorer For the study of Solar Eruptions) is a Franco-Chinese microsatellite mission. The scientific objectives of SMESE are the study of coronal mass ejections and flares. Its payload consists of three instrument packages : LYOT, DESIR and HEBS. LYOT is composed of a Lyman α (121.6 nm) coronagraph, a Lyman α disk imager and a far UV disk imager. DESIR is an infrared telescope working at 35 μm and 150 μm. HEBS is a high energy burst spectrometer working in X rays and γ rays covering the 10 keV to 600 MeV range. SMESE will be launched around 2011, providing a unique opportunity of detecting and understanding eruptions at the maximum activity phase of the solar cycle in a wide range of energies. The instrumentation on board SMESE is described in this paper.

We present a mission designed to address two main themes of the ESA Cosmic Vision Programme: the Evolution of the Universe and its Violent phenomena. ESTREMO/WFXRT is based on innovative instrumental and observational approaches, out of the mainstream of observatories of progressively increasing area, i.e.: Observing with fast reaction transient sources, like GRB, at their brightest levels, thus allowing high resolution spectroscopy. Observing and surveying through a X-ray telescope with a wide field of view and with high sensitivity extended sources, like cluster and Warm Hot Intragalactic Medium (WHIM). ESTREMO/WFXRT will rely on two cosmological probes: GRB and large scale X-ray structures. This will allow measurements of the dark energy, of the missing baryon mass in the local universe, thought to be mostly residing in outskirts of clusters and in hot filaments (WHIM) accreting onto dark matter structures, the detection of first objects in the dark Universe, the history of metal formation. The key asset of ESTREMO/WFXRT with regard to the study of Violent Universe is the capability to observe the most extreme objects of the Universe during their bursting phases. The large flux achieved in this phase allows unprecedented measurements with high resolution spectroscopy. The mission is based on a wide field X-ray/hard X-ray monitor, covering >1/4 of the sky, to localize transients; fast (min) autonomous follow-up with X-ray telescope (2000 cm²) equipped with high resolution spectroscopy transition edge (TES) microcalorimeters (2eV resolution below 2 keV) and with a wide field (1°) for imaging with 10" resolution (CCD) extended faint structures and for cluster surveys. A low background is achieved by a 600 km equatorial orbit. The performances of the mission on GRB and their use as cosmological beacons are presented and discussed.

The Monitor e Imageador de Raios-X (MIRAX) is a small (~250 kg) X-ray astronomy satellite mission designed to monitor the central Galactic plane for transient phenomena. With a field-of-view of ~1000 square degrees and an angular resolution of ~6 arcmin, MIRAX will provide an unprecedented discovery-space coverage to study X-ray variability in detail, from fast X-ray novae to long-term (~several months) variable phenomena. Chiefly among MIRAX science objectives is its capability of providing simultaneous complete temporal coverage of the evolution of a large number of accreting black holes, including a detailed characterization of the spectral state transitions in these systems. MIRAX's instruments will include a soft X-ray (2-18 keV) and two hard X-ray (10-200 keV) coded-aperture imagers, with sensitivities of ~5 and ~2.6 mCrab/day, respectively. The hard X-ray imagers will be built at the Instituto Nacional de Pesquisas Espaciais (INPE), Brazil, in close collaboration with the Center for Astrophysics & Space Sciences (CASS) of the University of California, San Diego (UCSD) and the Institut fur Astronomie und Astrophysik of the University of Tubingen (IAAT) in Germany; UCSD will provide the crossed-strip position-sensitive (0.5- mm spatial resolution) CdZnTe (CZT) hard X-ray detectors. The soft X-ray camera, provided by the Space Research Organization Netherlands (SRON), will be the spare flight unit of the Wide Field Cameras that flew on the Italian-Dutch satellite BeppoSAX. MIRAX is an approved mission of the Brazilian Space Agency (Agnecia Espacial Brasileira - AEB) and is scheduled to be launched in 2011 in a low-altitude (~550 km) circular equatorial orbit. In this paper we present recent developments in the mission planning and design, as well as Monte Carlo simulations performed on the GEANT-based package MGGPOD environment (Weidenspointner et al. 2004) and new algorithms for image digital processing. Simulated images of the central Galactic plane as it would be seen by MIRAX are shown.

A medium size satellite will be launched in the 2010-2011 timeframe into a 600 km equatorial (less than or equal to 5 deg.) orbit from Kourou or into a less than or equal to 30 deg. orbit from Baikonur as a fallback option. The payload includes eROSITA (extended ROentgen Survey with an Imaging Telescope Array, MPE, Germany) with 7 Wolter-type telescopes, the wide field X-ray monitor Lobster (LU, UK), the X-ray concentrator based on Kumakhov optics ART or coded-mask X-ray telescopes as a fallback (IKI, Russia) and GRB detector (Russian consortium). High particle background on high apogee orbits severely affects the capabilities of X-ray telescopes to study diffuse emission. For new baseline configuration of the SRG mission a low earth orbit was selected to circumvent this limitation. The mission will conduct the first all-sky survey with an imaging telescope in the 2-12 keV band to discover the hidden population of several hundred thousand obscured supermassive black holes and the first all-sky imaging X-ray time variability survey. In addition to the all-sky surveys it is foreseen to observe the extragalactic sky with high sensitivity to detect 50 to 100 thousand clusters of galaxies and thereafter to do follow-up pointed observations of selected sources, in order to investigate the nature of Dark Matter and Dark Energy. The new SRG mission would thus be a highly significant scientific and technological step beyond Chandra/XMM-Newton and would provide important and timely inputs for the next generation of giant X-ray observatories like XEUS/Con-X planned for the 2015-2025 horizon.

eROSITA (extended ROentgen Survey with an Imaging Telescope Array) will be one out of three main instruments on the Russian new Spectrum-RG mission which will be launched in the timeframe 2010-2011 into an equatorial Low Earth Orbit. The other two instruments are the wide field X-ray monitor Lobster (Leicester University, UK) and ART (IKI, Russia), an X-ray concentrator based on a Kumakhov optics. eROSITA consists of seven Wolter-I telescope modules similar to the German mission ABRIXAS which failed in 1999 and ROSITA, a telescope which was planned to be installed on the International Space Station ISS. Unlike these, the eROSITA telescope modules will be extended by adding another 27 mirror shells to the already existing ABRIXAS design. This will increase the effective area by a factor of ~5 at low energies. The additional shells do not contribute to the area at higher energies ( > 5 keV) due to the relative large grazing angles. Here we stay with the old ABRIXAS/ROSITA effective area. However, the primary scientific goal has changed since ABRIXAS: we are now aiming primarily for the detection of 50-100 thousands Clusters of Galaxies up to redshifts z > 1 in order to study the large scale structure in the Universe and test cosmological models including the Dark Energy, which was not yet known at ABRIXAS times. For the detection of clusters, a large effective area is needed at low (< 2 kev) energies. The mission scenario comprises a wide survey of the complete extragalactic area and a deep survey in the neighborhood of the Galactic Poles. Both are accomplished by an all-sky survey with a tilt of the rotation axis in order to shift the deepest exposures away from the ecliptic poles towards the galactic poles.

Some tests of fundamental physics - the equation of state at supra-nuclear densities, the metric in strong gravity, the effect of magnetic fields above the quantum critical value - can only be measured using compact astrophysical objects: neutron stars and black holes. The Extreme Physics Explorer is a modest sized (~500 kg) mission that would carry a high resolution (R ~300) X-ray spectrometer and a sensitive X-ray polarimeter, both with high time resolution (~5 μs) capability, at the focus of a large area (~5 sq.m), low resolution (HPD~1 arcmin) X-ray mirror. This instrumentation would enable new classes of tests of fundamental physics using neutron stars and black holes as cosmic laboratories.

X-Ray Polarimetry can be now performed by using a Micro Pattern Gas Chamber in the focus of a telescope. It requires large area optics for most important scientific targets. But since the technique is additive a dedicated mission with a cluster of small telescopes can perform many important measurements and bridge the 40 year gap between OSO-8 data and future big telescopes such as XEUS. POLARIX has been conceived as such a pathfinder. It is a Small Satellite based on the optics of JET-X. Two telescopes are available in flight configuration and three more can be easily produced starting from the available superpolished mandrels. We show the capabilities of such a cluster of telescopes each equipped with a focal plane photoelectric polarimeter and discuss a few alternative solutions.

The ISAS/JAXA Solar-B mission includes an Extreme-UV Imaging Spectrometer (EIS). It detects photons in the wavelength ranges 17 - 21 nm and 25 - 29 nm which include emission lines from several highly ionised species that exist at temperatures log T = 4.7, 5.6, 5.8, 5.9 and 6.0 - 7.3 K. Instrument throughput is increased substantially by the use of multilayer coatings optimized for maximum reflectance in the two selected wavelength bands. The use of back-illuminated CCDs provides significantly enhanced quantum efficiency over that previously available from microchannel plate systems. In this paper we will describe the design and operation of the instrument and present its performance parameters e.g. spectral and spatial resolution and sensitivity. Preliminary results of recent calibration measurements will be described. The role of EIS in the Solar-B mission will be illustrated with reference to the anticipated observing strategy for the first three months of the mission which will be outlined.

The Joint astrophysical Plasmadynamic EXperiment (J-PEX) is a high-resolution extreme ultraviolet (EUV) spectrometer (220-245 Å) used for the study of white dwarf atmospheres. Significant improvements have been achieved in both the normal-incidence gratings and the focal-plane detector since its first successful sounding rocket flight in 2001. The spherical laminar gratings have been replaced by paraboloidal gratings. The substrates of the new gratings have measured slope errors less than 0.35 arcsec. The gratings were recorded holographically and the rulings transferred into the silica substrates by ion etching. This procedure was followed by polymer overcoat to reduce the blaze angle of the groove profile. The detector uses microchannel plates with 6 μm pores and a cross-strip anode, providing 17.9 μm resolution in the dispersion direction. The detector employs a KBr photocathode with a projected efficiency of 0.24 at 256 Å. Using ray tracing simulations, we predict the resolving power expected from the spectrometer during upcoming EUV calibrations with a He II discharge source.

We have fabricated five new holographic ion-etched polymer-coated gratings for a reflight on a sounding rocket of the J-PEX high-resolution EUV spectrometer. The gratings are parabolic (nominal 2000-mm focal length), large (160 mm x 90 mm), and have a blazed groove profile of high density (3600 grooves/mm at the vertex). They have been coated with a high-reflectance multilayer of Mo/Si/C. Using an atomic force microscope, we examined grating topography before multilayer coating. The surface roughness is 2 angstrom rms and the blaze angle is near the target value of 2.4°. Using synchrotron radiation, we completed an efficiency calibration map of each multilayer-coated grating over the wavelength range 220-245 angstrom. At an angle of incidence of 5°, the average efficiency in the first inside order peaks near 234 angstrom. The average peak efficiency is 12.3 ± 1.0% for Grating 1, 12.6 ± 2.4% for Grating 2, 12.6 ± 1.8% for Grating 3, 14.1 ± 3.0% for Grating 4, and 13.0 ± 1.0% for Grating 5. The derived groove efficiency averaged over all gratings is approximately 50%, which meets our goals. Refined models of the multilayer gratings are required to resolve remaining issues.

The World Space Observatory Ultraviolet (WSO/UV) is a multi-national project grown out of the needs of the astronomical community to have future access to the ultraviolet range of the spectrum. The development of the WSO/UV S/C and the telescope is headed by the Russian Federal Space Agency (Roscosmos). The mission is scheduled to be launched in 2010 into the L2 orbit. The WSO/UV consists of a single Ultraviolet Telescope, incorporating a primary mirror of 1.7 m diameter feeding UV spectrometer and UV imagers. The UV spectrometer comprises three different single spectrographs, two high resolution echelle spectrographs - the High Resolution Double Echelle Spectrograph (HIRDES) - and a low dispersion long slit instrument. Within the HIRDES the spectral band (102 - 310 nm) is separated into two echelle spectrographs covering the UV range between 174- and 310 nm (UVES) and VacuumUV range between 102 and 176 nm (VUVES) with a very high spectral resolution of > 50000. Each spectrograph encompass a stand alone optical bench structure with a fully redundant high speed MCP detector system, the optomechanics and a network of mechanisms with different functionalities. The fundamental technical concept is based on the heritage of the two previous ORFEUS SPAS missions. The phase B1 development activities are described in this paper under consideration of performance aspects, design drivers, the related trade offs (e.g. mechanical concepts, material selection etc.) and the critical functional and environmental test verification approach. Furthermore the actual state of the other scientific instruments of the WSO/UV (e.g. UV imagers) project is described.

GALEX is a NASA Small Explorer mission that was launched in April 2003 and is now performing a survey of the sky in the far and near ultraviolet (FUV and NUV, 155 nm and 220 nm, respectively). The instrument comprises a 50 cm Ritchey-Chretien telescope with selectable imaging window or objective grism feeding a pair of photon-counting, microchannel-plate, delay-line readout detectors through a multilayer dichroic beamsplitter. The baseline mission is approximately 50% complete, with the instrument meeting its performance requirements for astrometry, photometry and resolution. Operating GALEX with a very small team has been a challenge, yet we have managed to resolve numerous satellite anomalies without loss of performance (only efficiency). Many of the most significant operations issues of our successful ongoing mission will be reported here along with lessons for future projects.

We present proof-of-concept results for a novel ultraviolet-sensitive, photon counting, solar blind detector that has the potential for high QE in a compact low voltage, low power, unsealed design. We utilize a delta-doped back-illuminated CCD to read out low energy electrons from a photocathode. In parallel, a new generation of high-QE ultraviolet-sensitive GaN photocathodes is being developed with initial success using delta-doping technology rather than cesiation. In this paper we present results with the new readout using a CsI test cathode, which produces events at under 1000 V accelerating potential.

Current multilayer designs for 10-80 keV hard X-ray telescope missions have focused primarily on the proven properties of W and Pt based multilayer coatings. Recently a number of new material combinations and coating capabilities have emerged which allows for more elaborate designs that can further extend the energy band of current mission designs as well as avoid some of the unwanted absorption edge effects in the effective area near potentially important line emission energies. These new design possibilities are investigated for current hard X-ray mission designs. The new material combinations to be considered are recently proven capabilities of enhanced NiV/C coatings and NiV/SiC coatings in conjuction with the well-established W based coatings.

The materials chosen for depth graded multilayer designs for hard x-ray telescopes (10 keV to 80 keV) have until now been focusing on W/Si, W/SiC, Pt/C, and Pt/SiC. These material combinations have been chosen because of good stability over time and low interface roughness, However both W and Pt have absorption edges in the interesting energy range from 70 - 80 keV. If looking at the optical constants Cu and Ni would be good alternative high-Z candidates since the k-absorption edges in Cu and Ni is below 10 keV. We have investigated both of these materials as the reflecting layer in combination with SiC as the spacer layer and give the performance in terms of roughness, minimum obtainable d-spacing and stability over time as deposited in our planar magnetron sputtering facility. Likewise we review the same properties of WC/SiC coatings which we have previously developed and which allow for very small d-spacings. The combination of WC/SiC or the well established W/SiC with the above mentioned Cu and Ni-containing multilayers in the same stack allows for novel telescope designs operating up to and above 100 keV without the absorption edge structure.

Future hard X-ray telescopes (e.g. SIMBOL-X and Constellation-X) will make use of hard X-ray optics with multilayer coatings, with angular resolutions comparable to the achieved ones in the soft X-rays. One of the crucial points in X-ray optics, indeed, is multilayer interfacial microroughness that causes effective area reduction and X-Ray Scattering (XRS). The latter, in particular, is responsible for image quality degradation. Interfacial smoothness deterioration in multilayer deposition processes is commonly observed as a result of substrate profile replication and intrinsic random deposition noise. For this reason, roughness growth should be carefully investigated by surface topographic analysis, X-ray reflectivity and XRS measurements. It is convenient to express the roughness evolution in terms of interface Power Spectral Densities (PSD), that are directly related to XRS and, in turn, in affecting the optic HEW (Half Energy Width). In order to interpret roughness amplification and to help us to predict the imaging performance of hard X-ray optics, we have implemented a well known kinetic continuum equation model in a IDL language program (MPES, Multilayer PSDs Evolution Simulator), allowing us the determination of characteristic growth parameters in multilayer coatings. In this paper we present some results from analysis we performed on several samples coated with hard X-ray multilayers (W/Si, Pt/C, Mo/Si) using different deposition techniques. We show also the XRS predictions resulting from the obtained modelizations, in comparison to the experimental XRS measurements performed at the energy of 8.05 keV.

Graded depth multi-layer coatings have the potential to optimise the performance of X-ray reflective surfaces for improved energy response. A study of deposition techniques on silicon substrates representative of the XEUS High Performance Pore Optics (HPO) technology has been carried out. Measurements at synchrotron radiation facilities have been used to confirm the excellent performance improvements achievable with Mo/Si and W/Si multilayers. Future activities that will be necessary to implement such coatings in the HPO assembly sequence are highlighted. Further coating developments that may allow an optimisation of the XEUS effective area in light of potential changes to science requirements and telescope configurations are also identified. Finally an initial measurement of effects of radiation damage within the multilayers is reported.

Japan's 6th X-ray satellite mission NeXT has completed pre-Phase-A study, and is waiting to advance to Phase-A/B. The X-Ray Telescope System onboard NeXT covers wide energy range from 0.3 to 80 KeV. The paper reviews current status on design and technology of the mission as written in the NeXT Mission Proposal on Oct. 2005.

Future hard (10-100 keV) X-ray telescopes (SIMBOL-X, Con-X, HEXIT-SAT, XEUS) will implement focusing optics with multilayer coatings: in view of the production of these optics we are exploring several deposition techniques for the reflective coatings. In order to evaluate the achievable optical performance X-Ray Reflectivity (XRR) measurements are performed, which are powerful tools for the in-depth characterization of multilayer properties (roughness, thickness and density distribution). An exact extraction of the stack parameters is however difficult because the XRR scans depend on them in a complex way. The PPM code, developed at ERSF in the past years, is able to derive the layer-by-layer properties of multilayer structures from semi-automatic XRR scan fittings by means of a global minimization procedure in the parameters space. In this work we will present the PPM modeling of some multilayer stacks (Pt/C and Ni/C) deposited by simple e-beam evaporation. Moreover, in order to verify the predictions of PPM, the obtained results are compared with TEM profiles taken on the same set of samples. As we will show, PPM results are in good agreement with the TEM findings. In addition, we show that the accurate fitting returns a physically correct evaluation of the variation of layers thickness through the stack, whereas the thickness trend derived from TEM profiles can be altered by the superposition of roughness profiles in the sample image.

Silicon pore optics have been proposed earlier as modular optical X-ray units in large Wolter-I telescopes that would match effective area and resolution requirements imposed by missions such as XEUS. Since then the optics have been developed further and the feasibility of the production of high-performance pore optics has been demonstrated. Optimisation of the production and the assembly process allowed the generation of optics with larger areas with improved imaging performance; Silicon pore optics can now be manufactured with properties required for future X-ray telescopes. A suitable design that allows the implementation of pore optics into X-ray Optical Units in Wolter I configuration was derived and recently built including an appropriate telescope mounting structure with interfaces for the individual components. Based on the present experience the requirements for industrial mirror production, optics assembly, related metrology and performance verification are reviewed from a viewpoint of its implementation into a large scale production. Such production may lead to the provision of the large number of X-ray optical units that are required within reasonably short time scales and a feasible cost envelope. The present outcome of this investigation and the prospects to future production and test facilities will be presented.

It has been demonstrated that silicon pore optics can serve as the new technology for building the next generation of X-ray telescopes for astronomical missions. In order to build up an optic in Wolter-I configuration, the high performance pore optics (HPO) have to be co-aligned and integrated into pairs, forming so-called X-ray optical units (XOU). The stringent co-alignment requirements for a 50 m focal length telescope like XEUS (e.g. 1 arcsecond between parabolic and hyperbolic HPO) demand holistic alignment concepts, which integrate the metrology, the fixation and the performance verification. The application in space and the resulting thermal requirements in combination with launch loads and other mechanical restrictions must also be considered. Finite element modelling of different fixation mechanisms and XOU configurations allow one both to assess difficulties at an early stage and to validate solution strategies. This paper reports on the concepts, which have been developed. The most promising candidate has been selected to build a form fit function model. The experimental set-up to align the HPOs, the required metrology and first results of the performance verification at test facilities will be shown and discussed.

New astronomical science missions demand X-ray telescopes with an angular resolution better than 5" and effective areas of up to 5 m² at 1 keV. Traditional technologies like nickel electro-forming or polished glass surfaces lead to long and heavy structures, which require prohibitive mass resources to achieve the required large collecting area. To overcome this problem an entirely novel technology using silicon wafers has been developed resulting in pore X-ray optics, which form very light, stiff and modular structures. The suitability of silicon wafers to be used as high quality optical material has been demonstrated and semiconductor industry have developed methods to structure the wafers such, that they can be assembled into segments of Wolter-I optics. For the assembly of these, so called High Performance Pore Optics (HPO), we have developed an automated production robot. The assembly process and the required metrology is described in detail and experimental methods are shown, which allow to assess the quality of the HPOs during production and to predict their performance when measured in synchrotron radiation facilities.

ESA is developing technologies for x-ray imaging to reduce the mass and volume of future missions. Applications of x-ray optics are foreseen in future planetary x-ray imagers, x-ray timing observatories and in observatories for high-energy astrophysics. With reference to planetary x-ray imagers the use of glass micro-pore material is being investigated. This technology allows the formation of a monolithic, glass structure that can be used to focus x-rays by glancing reflections off the pore walls. A technique to form x-ray focusing plates that contain thousands of square micro-pores has been developed with Photonis. The square pores are formed in a process that fuses blocks of extruded square fibres, which can then be sliced, etched and slumped to form the segment of an optic with a specific radius. A proposed imager would be created from 2 optics, slumped with different radii, and mounted to form an approximation of a Wolter I optic configuration. Reflection can be improved by coating the channel surfaces with a heavy element, such as nickel. Continuing developments have been made to enhance the manufacturing processes and improve the characteristics of the manufactured x-ray focusing plates, such as improved surface roughness and squareness of pore walls, improved pore alignment from fibre stacking through to optic segment slumping and development of pore wall coatings. In order to measure improvements x-ray measurements are performed by ESA and cosine Research BV, using the BESSY-II synchrotron facility four-crystal monochromator beamline of the Physikalisch-Technische Bundesanstalt, on multifibres, sectors and slumped sectors. A probing beam is used to investigate a number of pores to determine x-ray transmission, focussing characteristics as they relate to the overall transmission, x-ray reflectivity of channel walls, radial alignment of fibres, slumping radius and fibre position in a fused block. SEM measurements and microscope inspection have also been used to inspect the channel walls and determine improvements made in fibre stacking and coating.

Recent development of the extremely light-weight micro pore optics based on the semiconductor MEMS (Micro Electro Mechanical System) technologies is reported. Anisotropic chemical wet etching of silicon (110) wafers were utilized, in order to obtain a row of smooth (111) side walls vertical to the wafer face and to use them as X-ray mirrors. To obtain high performance mirrors with smooth surfaces and a high aspect ratio, several modifications were made to our previous manufacturing process shown in Ezoe et al. (2005). After these improvements, smooth surfaces with rms roughness of the order of angstroms and also a high aspect ratio of 20 were achieved. Furthermore, a single-stage optic was designed as a first step to multi-stage optics. A mounting device and a slit device for the sample optic were fabricated fully using the MEMS technologies and evaluated.

The Constellation-X mission planned for launch in 2015-2020 timeframe, will feature an array of Hard X-ray telescopes (HXT) with a total collecting area greater than 1500 cm² at 40 keV. Two technologies are being investigated for the optics of these telescopes, one of which is multilayer-coated Electroformed-Nickel-Replicated (ENR) shells. The attraction of the ENR process is that the resulting full-shell optics are inherently stable and offer the prospect of better angular resolution which results in lower background and higher instrument sensitivity. We are building a prototype HXT mirror module using an ENR process to fabricate the individual shells. This prototype consists of 5 shells with diameters ranging from 15 cm to 28 cm with a length of 42.6 cm. The innermost of these will be coated with iridium, while the remainder will be coated with graded d-spaced W/Si multilayers. The assembly structure has been completed and last year we reported on full beam illumination results from the first test shell mounted in this structure. We have now fabricated and coated two (15 cm and 23 cm diameter) 100 micron thick shells which have been aligned and mounted. This paper presents the results of full beam illumination X-ray tests, taken at MPE-Panter. The HEW of the individual shells will be discussed, in addition to results from the full two shell optic test.

We have developed advanced thin-foil substrates with a two-stage reflector for a large X-ray telescope. We successfully formed a magnesium foil with a figure error of a peak-to-peak value of 60 μm. This figure error has allowed a replication method in order to obtain smooth surface. We made a glass mandrel precisely shaped Wolter type-I optics by using the ELID method, then applied the replication to a 200 mm length aluminum foil at Nagoya University. After the replication, the figure error of the foil was improved by as much as factor 10. We evaluated the image quality of the replicated foil by using a collimated optical light at Ehime University, and we demonstrated the potential of the replication method. We report a current status of the development of the replication method.

To search for warm-hot intergalactic medium (WHIM), a small satellite mission DIOS (Diffuse Intergalactic Oxygen Surveyer ) is planned and a specially designed four-stage X-ray telescope (FXT) has been developed as the best fit optics to have a wide field of view and a large effective area. Based on the previous works such as the design of optics and replica foil mirror fabrication, we made the demonstration model of the FXT, which has a set of four-stage mirror supported by alignment plates to reduce alignment errors between different stages. On the selection of mirror surface metrial, we tried to increase the reflectivity of gold or platinum replica mirror at low energies. We are also trying to make Ni replica mandrel having the shape of four different cone angles for developing a full or partial shell of four-stage mirror formed in a same substrate. We describe the expected performance and alignment procedure of the demonstration model, the present status of the selection of mirror surface material and the development of Ni mandrel.

In our ongoing studies of high precision glass slumping we have successfully formed the first Wolter-I X-ray mirror segments with parabola and hyperbola in one piece. It could be demonstrated that the excellent surface roughness of the 0.55 mm thick display glass chosen is conserved during the slumping process. The influence of several parameters of the process, such as maximum temperature, heating and cooling rates etc. have to be measured and controlled with adequate metrology. Currently, we are optimizing the process to reduce the figure errors down to 1 micrometer what will be the starting point for further, final figure error corrections. We point out that metrology plays an important role in achieving a high precision optics, i.e. an angular resolution of a few arcsec. In this paper we report on the results of our studies and discuss them in the context of the requirements for future X-ray telescopes with large apertures.

The thermally formed thin glass foils and optically shaped Si wafers are considered to belong to the most promising technologies for future large space X-ray telescopes. We present and discuss the recent progress in these technologies, as well as properties of test mirrors produced and tested. For both technologies, both flat and curved samples have been produced and tested. The achieved profile accuracy is of order of 1 micrometer or better, while the bending technologies maintain the intrinsic fine surface microroughness of substrates (better than 0.5 nm for glass and around 0.1 nm for Si wafers).

We are developing hard-x-ray optics using an electroformed-nickel-replication process off superpolished mandrels. To date, we have fabricated over 100 shells for our HERO balloon payload with typical angular resolutions in the 13-15 arcsec range. This paper discusses the factors currently limiting this resolution and various developments geared towards the production of higher-resolution optics.

The quantitative study of the changes in the behavior of structures with scale is one of the oldest areas of physics: it was one of Galileo's "Two New Sciences". Nevertheless, it does not have the appreciation it deserves among high energy astrophysicists. While most understand the importance of collecting area and resolution, the connection between them is less well known. This matters: to make a good instrument one must exploit the applied physics, not fight against it. I will discuss counter-intuitive consequences of some well known scaling laws. I will show that for imaging instruments detector linear resolution is an under-appreciated performance driver. I will discuss the tradeoffs between modularization and integration. Attention to scaling issues has the potential to enable world class science from small instruments, increase the productivity of larger instruments, and transform extremely large instruments from impractical fantasies to practical realities.

X-rays provide one of the few bands through which we can study the epoch of reionization, when the first galaxies, black holes and stars were born. To reach the sensitivity required to image these first discrete objects in the universe needs a major advance in X-ray optics. Generation-X (Gen-X) is currently the only X-ray astronomy mission concept that addresses this goal. Gen-X aims to improve substantially on the Chandra angular resolution and to do so with substantially larger effective area. These two goals can only be met if a mirror technology can be developed that yields high angular resolution at much lower mass/unit area than the Chandra optics, matching that of Constellation-X (Con-X). We describe an approach to this goal based on active X-ray optics that correct the mid-frequency departures from an ideal Wolter optic on-orbit. We concentrate on the problems of sensing figure errors, calculating the corrections required, and applying those corrections. The time needed to make this in-flight calibration is reasonable. A laboratory version of these optics has already been developed by others and is successfully operating at synchrotron light sources. With only a moderate investment in these optics the goals of Gen-X resolution can be realized.

Future X-ray telescopes invariably require much higher angular resolutions and/or much larger effective areas than those already flown, and they will typically be designed and built with mirror segments, in contrast with the typical past X-ray telescope of complete shells. While the segmented approach has many advantages, it has one significant disadvantage: its complexity and difficulty associated with mirror segment alignment and integration. In this paper, we outline an approach, named "Fabricate and Assemble," that directly addresses this disadvantage. We will describe the necessary components, their fabrication, and their integration into a mirror assembly. The salient features of this approach include: (1) it fully realizes the optical performance potential of each mirror segment, (2) it leaves each mirror in a stress-free or minimally stressed state, resulting in a stress-free and therefore stable mirror assembly, (3) it assembles the mirror segment while it is supported so as to minimize or even eliminate the effect of gravity, and (4) it is highly amenable to being implemented as part of a sequential production line.

XEUS is the potential successor to ESA's XMM-Newton X-ray observatory and is being proposed in response to the Cosmic Vision 2015-2025 long term plan for ESA's Science Programme. A new mission configuration was developed in the last year, accommodating the boundary conditions of a European-led mission with a formation-flying mirror and detector spacecraft in L2 with a focal length of 35m and an effective area of >5 m² at 1 keV. Here the new capabilities are compared with the key scientific questions presented to the Cosmic Vision exercise: the evolution of large scale structure and nucleosynthesis, the co-evolution of supermassive black holes and their host galaxies, and the study of matter under extreme conditions.

We describe recent progress in the technology development program for the mirror system for the Constellation-X Spectroscopy X-ray Telescope (SXT). Development of this mirror represents a significant technology challenge, as it must provide a combination of large effective area (3 sq. m) and modest angular resolution (15 arc second half power diameter requirement; 5 arc second goal) with a limited mass allocation. The baseline design incorporates over 200 nested Wolter 1 mirrors. Each of these in turn is segmented in order to simplify handling of the mirrors and facilitate mass production. The X-ray reflecting surfaces are fabricated from thin, thermally formed glass sheets. Production improvements have yielded mirror segments that approach the performance requirement without the need for epoxy replication. A mounting and alignment approach incorporating piezoelectric actuators has been shown to manipulate mirror segments with the required precision without introducing significant distortion. Substantial improvements in metrology methodology have provided insights into the mirror segment forming and alignment processes. We describe the technical advances made over the past year and summarize near-term plans.

XEUS is the potential successor to ESA's XMM-Newton X-ray observatory and is being proposed in response to the Cosmic Vision 2015-2025 long term plan for ESA's Science Programme. Novel light-weight optics with an effective area of 5 m² at 1 keV and 2 m² at 7 keV and 2-5" HEW spatial resolution together with advanced detectors will provide much improved imaging, spectroscopic and timing performances and open new vistas in X-ray astronomy in the post 2015 timeframe. XEUS will allow the study of the birth, growth and spin of the super-massive black holes in early AGN, allow the cosmic feedback between galaxies and their environment to be investigated through the study of inflows and outflows and relativistic acceleration and allow the growth of large scale structures and metal synthesis to be probed using the hot X-ray emitting gas in clusters of galaxies and the warm/hot filamentary structures observable with X-ray absorption spectroscopy. High time resolution studies will allow the Equation of State of supra-nuclear material in neutron stars to be constrained. These science goals set very demanding requirements on the mission design which is based on two formation flying spacecraft launched to the second Earth-Sun Lagrangian point by an Ariane V ECA. One spacecraft will contain the novel high performance optics while the other, separated by the 35 m focal length, will contain narrow and wide field imaging spectrometers and other specialized instruments.

XEUS, the 'X-ray Early Universe Spectroscopy Mission', is a potential candidate for inclusion into the Cosmic Visions 1525 Science Programme of the European Space Agency ESA [1,2]. It is being studied jointly with the Japanese Aerospace Exploration Agency JAXA. The newly developed Silicon-based High resolution Pore Optics (HPO) combines low mass density with good angular resolution, and enables the development of novel mission design concepts for the implementation of a new generation of space based X-ray telescope [3, 4, 5]. This optics technology allows also for the application of complex reflective coatings [6], improving the effective area of the telescope and permitting an enhancement in the engineering of the desired response function. This paper gives an overview of the telescope optical design and optical bench architecture, including the deployment scheme. Further, the performance predictions based on ray tracing are discussed and the overall telescope design of XEUS is presented.

The characteristics of the latest generation of assembled silicon pore X-ray optics are discussed in this paper. These very light, stiff and modular high performance pore optics (HPO) have been developed [1] for the next generation of astronomical X-ray telescopes, which require large collecting areas whilst achieving angular resolutions better than 5 arcseconds. The suitability of 12 inch silicon wafers as high quality optical mirrors and the automated assembly process are discussed elsewhere in this conference. HPOs with several tens of ribbed silicon plates are assembled by bending the plates into an accurate cylindrical shape and directly bonding them on top of each other. The achievable figure accuracy is measured during assembly and in test campaigns at X-ray testing facilities like BESSY-II and PANTER. Pencil beam measurements allow gaining information on the quality achieved by the production process with high spatial resolution. In combination with full beam illumination a complete picture of the excellent performance of these optics can be derived. Experimental results are presented and discussed in detail. The results of such campaigns are used to further improve the production process in order to match the challenging XEUS requirements [2] for imaging resolution and mass.

The XEUS petals encompass the optical bench structure of the stand alone X-Ray Optical Units (XOU) based on the high performance and light weight Silicon Pore Optics technology. The performance aspects under consideration of the design drivers, the related trade offs (e.g. mechanical concepts, material selection, XOU butting efficiency etc.) and the current development activities wrt. the design, manufacturing, assembly and the functional and environmental test verification approach of the Form Fit Function Model are described in this paper. Special emphasis is given to the critical external optical and mechanical interfaces coherent to the mission design, e.g. the Mirror S/C frame work structure and the Detector S/C. The technology program is based on the heritage achieved within the context of the XMM/Newton telescope development. The investigations of the correlated programmatic aspects towards the FM production by application of effective robot system supported assembly procedures shall be illustrated.

Constellation-X is NASA's next major X-ray observatory. It requires X-ray mirrors with high throughput (3 m² effective area at 1 keV), moderate angular resolution (15" half power diameter), and light weight (about an order of magnitude lighter than XMM/Newton's). Over the past few years we have been developing a glass forming technology for making mirrors. This technology by construction meets from the outset two (throughput and weight) of the three requirements. Our development effort has been concentrated on improving the angular resolution. Our progress so far has shown that this technology not only can meet the angular resolution requirement of 15" HPD, but also has the potential to reach Constellation-X's goal of 5" HPD. This paper is a snapshot of our X-ray mirror development effort as of May 2006. It briefly describes the mirror fabrication process, results achieved, and important issues that are being worked on.

A single Constellation-X Spectroscopy X-ray Telescope (SXT) mirror segment pair is being aligned in the Optical Alignment Pathfinder 2 (OAP2) platform using a combination of mechanical and optical techniques. Coarse positioning was provided through a contact probe, the alignment was refined in a collimated while-light facility used for the Suzaku (ASTRO-E2) satellite, and then finalized with a combination of a Centroid Detector Assembly (CDA) and an interferometer coupled to a novel conical null lens providing surface map imaging over 60% of the mirror surface at one time. Due to a variety of reasons, the positioning and figure of the mirror segment under examination can shift, and we test how reliably high quality alignment can be reproduced on any given day. Also, the mirror segment's deformation response to deliberate misalignments has been tested, providing a response matrix for these thin glass mirror segments.

The Constellation-X Reflection Grating Spectrometer (RGS) is designed to provide high-throughput, high-resolution spectra in the long wavelength band of 6 to 50 angstrom. In the nominal design an array of reflection gratings is mounted at the exit of the Spectroscopy X-ray Telescope (SXT) mirror module. The gratings intercept and disperse light to a designated array of CCD detectors. To achieve the throughput (A_eff > 1000 cm² below 0.6 keV) and resolution (Δλ/λ > 300 below 0.6 keV) requirements for the instrument we are investigating two possible grating designs. The first design uses in-plane gratings in a classical configuration that is very similar to the XMM-Newton RGS. The second design uses off-plane gratings in a conical configuration. The off-plane design has the advantage of providing higher reflectivity and potentially, a higher spectral resolution than the in-plane configuration. In our presentation we will describe the performance requirements and the current status of the technology development.

With its large collecting area XEUS will be ideally suited to probe strong gravity fields around collapsed objects and to constrain the equation of state of dense matter in neutron stars. For these studies, detectors are needed which can measure 10⁶ events/sec with high time resolution (10 μsec) and good energy resolution (ΔE = 200 - 300 eV FWHM) combined with an energy and flux independent dead time. The current baseline for a dedicated fast timing detector on XEUS is an array of 19 silicon drift detectors (SDD) operated as single photon detectors. Optionally we have studied an array of 40 x 20 SDD/DEPFET macro pixel detectors read out at a constant frame rate of 10⁵/sec. Alternatively to these two dedicated detectors, a high time resolution mode of the Wide Field Imager (1024 x 1024 DEPFET array with 78μm x 78μm pixels) is considered here. We have simulated the expected timing performance of these detector options based on results from laboratory measurements. We have performed Monte Carlo simulations using the latest available XEUS mirror response files for Crab like sources and intensities ranging from 10² up to 4x10⁶ events/sec. Our results are discussed in the light of the scientific requirements for fast timing as expressed in the ESA Cosmic Vision 2015-2025 plan.

EURECA (EURopean-JapanEse Calorimeter Array) comprises a 5 x 5 pixel imaging TES-based micro-calorimeter array read-out by SQUID-based frequency-domain-multiplexed electronics and cooled down by an adiabatic demagnetization refrigerator. A European-Japanese consortium designs, fabricates, and tests this prototype instrument with the aim to show within about 2 years technology readiness of a TES-based X-ray imaging micro-calorimeter array in anticipation of future X-ray astronomy missions, like XEUS (ESA), Constellation-X (NASA), NEXT (JAXA), DIOS (JAXA), ESTREMO (ASI), and NEW (Dutch-multinational). This paper describes the instrument concept, and shows the design of the various sub-units, like the TES detector array, LC-filters, SQUID-amplifiers, flux-locked-loop electronics, AC-bias sources, etc.

We have been developing x-ray microcalorimeters for the Constellation-X mission. Devices based on superconducting transition-edge sensors (TES) have demonstrated the potential to meet the Constellation-X requirements for spectral resolution, speed, and array scale (> 1000 pixels) in a close-packed geometry. In our part of the GSFC/NIST collaboration on this technology development, we have been concentrating on the fabrication of arrays of pixels suitable for the Constellation-X reference configuration. We have fabricated 8x8 arrays with 0.25-mm pixels arranged with 92% fill factor. The pixels are based on Mo/Au TES and Bi/Cu or Au/Bi absorbers. We have achieved a resolution of 4.0 eV FWHM at 6 keV in such devices, which meets the Constellation-X resolution requirement at 6 keV. Studies of the thermal transport in our Bi/Cu absorbers have shown that, while there is room for improvement, for 0.25-mm pixels the standard absorber design is adequate to avoid unacceptable line-broadening from position dependence caused by thermal diffusion. In order to improve reproducibility and to push closer to the 2-eV goal at 6 keV, however, we are refining the design of the TES and the interface to the absorber. Recent efforts to introduce a barrier layer between the Bi and the Mo/Au to avoid variable interface chemistry and thus improve the reproducibility of device characteristics have thus far yielded unsatisfactory results. However, we have developed a new set of absorber designs with contacts to the TES engineered to allow contact only in regions that do not serve as the active thermometer. We have further constrained the design so that a low-resistance absorber will not electrically short the TES. It is with such a design that we have achieved 4.0 eV resolution at 6 keV.

Nuclear astrophysics presents an extraordinary scientific potential for the study of the most powerful sources and the most violent events in the Universe. In order to take full advantage of this potential, the next generation of instrumentation for this domain will have to achieve a factor of 10-100 improvement in sensitivity over present technologies. With the development of a Laue Lens we have taken up this challenge: gamma-rays are focused from the large collecting area of a crystal diffraction lens onto a very small detector volume. As a consequence, the background noise is extremely low, making possible unprecedented sensitivities. The detector, a solid state Compton Camera, provides high spectral and angular resolution, and the capability of measuring the polarization of the incident photons. Based on the measured performance of our prototype gamma-ray lens CLAIRE, a mission concept of a space borne Laue lens telescope is outlined. A Laue lens telescope addresses a wide range of fundamental astrophysical questions such as the life cycles of matter and the behavior of matter under extreme conditions. Amongst the primary scientific objectives of a Laue lens telescope is the study of type Ia supernovae by measuring intensities, shifts and shapes of their nuclear gamma-ray lines. Moreover, the sensitive gamma-ray line spectroscopy performed with a Laue lens telescope is expected to clarify the nature of galactic microquasars (e-e+ annihilation radiation from the jets), neutron stars and pulsars, X-ray Binaries, AGN, solar flares and gamma-ray afterglow from gamma-burst counterparts.

Observations of the gamma-ray sky reveal the most powerful sources and the most violent events in the Universe. While at lower wavebands the observed emission is generally dominated by thermal processes, the gamma-ray sky provides us with a view on the non-thermal Universe. Here particles are accelerated to extreme relativistic energies by mechanisms which are still poorly understood, and nuclear reactions are synthesizing the basic constituents of our world. Cosmic accelerators and cosmic explosions are the major science themes that are addressed in the gamma-ray regime. With the INTEGRAL observatory, ESA has provided a unique tool to the astronomical community revealing hundreds of sources, new classes of objects, extraordinary views of antimatter annihilation in our Galaxy, and fingerprints of recent nucleosynthesis processes. While INTEGRAL provides the global overview over the soft gamma-ray sky, there is a growing need to perform deeper, more focused investigations of gamma-ray sources. In soft X-rays a comparable step was taken going from the Einstein and the EXOSAT satellites to the Chandra and XMM/Newton observatories. Technological advances in the past years in the domain of gamma-ray focusing using Laue diffraction and multilayer-coated mirror techniques hav paved the way towards a gamma-ray mission, providing major improvements compared to past missions regarding sensitivity and angular resolution. Such a future Gamma-Ray Imager will allow to study particle acceleration processes and explosion physics in unprecedented detail, providing essential clues on the innermost nature of the most violent and most energetic processes in the Universe.

The Advanced Compton Telescope (ACT), the next major step in gamma-ray astronomy, will probe the fires where chemical elements are formed by enabling high-resolution spectroscopy of nuclear emission from supernova explosions. During the past two years, our collaboration has been undertaking a NASA mission concept study for ACT. This study was designed to (1) transform the key scientific objectives into specific instrument requirements, (2) to identify the most promising technologies to meet those requirements, and (3) to design a viable mission concept for this instrument. We present the results of this study, including scientific goals and expected performance, mission design, and technology recommendations.

The Nuclear Compton Telescope (NCT) is a balloon-borne soft gamma-ray (0.2MeV-10MeV) telescope designed to study astrophysical sources of nuclear line emission and polarization. A prototype instrument was successfully launched from Ft. Sumner, NM on June 1, 2005. The NCT prototype consists of two 3D position sensitive High-Purity-Germanium (HPGe) strip detectors fabricated with amorphous Ge contacts. The novel ultra-compact design and new technologies allow NCT to achieve high efficiencies with excellent spectral resolution and background reduction. Energy and positioning calibration data was acquired pre-flight in Fort Sumner, NM after the full instrument integration. Here we discuss our calibration techniques and results, and detector efficiencies. Comparisons with simulations are presented as well.

A breakthrough in the sensitivity level of the hard X-/gamma-ray telescopes, which today are based on detectors that view the sky through (or not) coded masks, is expected when focusing optics will be available also in this energy range. Focusing techniques are now in an advanced stage of development. To date the most efficient technique to focus hard X-rays with energies above 100 keV appears to be the Bragg diffraction from crystals in transmission configuration (Laue lenses). Crystals with mosaic structure appear to be the most suitable to build a Laue lens with a broad passband, even though other alternative structures are being investigated. The goal of our project is the development of a broad band focusing telescope based on gamma-ray lenses for the study of the continuum emission of celestial sources from 60 keV up to >600 keV. We will report details of our project, its development status and results of our assessment study of a lens configuration for the European Gamma Ray Imager (GRI) mission now under study for the ESA plan Cosmic Vision 2015-2025.

The High Energy X-ray Imager Survey (HEXIS) Coded Mask balloon instrument will test the performance of the electronics and the detector for the proposed MIRAX satellite mission, and measure the background in a near space environment. HEXIS is a Coded Mask Imager based upon a 100 x 100mm Tungsten MURA mask and a set of four Cadmium-Zinc-Telluride (CZT) crossed strip detectors assembled as one detector module with 40 cm² detector area and 0.5mm pitch strips creating an effective 126 x 126 grid of 0.5 x 0.5mm² pixels. Each detector strip can be read out individually using Readout Electronics for Nuclear Application (RENA)-ASICs developed by NOVA R&D. The system has an operating energy range of <10 to 200 keV. The telescope has a passive shield as part of the instrument structure, which is surrounded by an active anti-coincidence shield of plastic scintillators with embedded wavelength shifting and light transmitting fibers. The first HEXIS balloon flight is planned for Spring 2007. We present the lab performance for one module using RENA ASICs and for the scintillator shield. The MIRAX Hard X-ray Imager (HXI) will contain two cameras with 9 detector modules each.

With focusing of gamma rays in the nuclear-line energy regime establishing itself as a feasible and very promising approach for high-sensitivity gamma-ray studies of individual sources, optimizing the focal plane instrumentation for gamma-lens telescopes is a prime objective. The detector of choice for a focusing nuclear-line spectroscopy mission would be the one with the best energy resolution available over the energy range of interest: Germanium. Using a Compton detector focal plane has three advantages over monolithic detectors: additional knowledge about (Compton) events enhances background rejection capabilities, the inherently finely pixellated detector naturally allows the selection of events according to the focal spot size and position and could enable source imaging, and Compton detectors are inherently sensitive to gamma-ray polarization. Suitable Ge-strip detectors that could be assembled into a sensitive high-resolution focal plane for a gamma-ray lens are available today. They have been extensively tested in the laboratory and flown on the Nuclear Compton Telescope balloon from Ft. Sumner in 2005. In the course of the ACT vision mission study, an extensive simulation and analysis package for Compton telescopes has been assembled. We leverage off this work to explore achievable sensitivities for different Ge Compton focal plane configurations - and compare them to sensitivities achievable with less complex detectors - as a step towards determining an optimum configuration.

The energy range above 50 keV is important for the study of many open problems in high energy astrophysics such as, non thermal mechanisms in SNR, the study of the high energy cut-offs in AGN spectra, and the detection of nuclear and annihilation lines. In the framework of the definition of a new mission concept for hard X and soft gamma ray (GRI- Gamma Ray Imager) for the next decade, the use of Laue lenses with broad energy band-passes from 100 to 1000 keV is under study. This kind of instruments will be used for deep study the hard X-ray continuum of celestial sources. This new telescope will require focal plane detectors with high detection efficiency over the entire operative range, an energy resolution of few keV at 500 keV and a sensitivity to linear polarization. We describe a possible configuration for the focal plane detector based on CdTe/CZT pixelated layers stacked together to achieve the required detection efficiency at high energy. Each layer can either operate as a separate position sensitive detector and a polarimeter or together with other layers in order to increase the overall full energy efficiency. We report on the current state of art in high Z spectrometers development and on some activities undergoing. Furthermore we describe the proposed focal plane option with the required resources and an analytical summary of the achievable performance in terms of efficiency and polarimetry.

The development of formation flying technology in space has opened a new window for astronomy at hard X-γ-ray wavelenghts, allowing observations with unprecedented angular resolution (location accuracy of the order of few arcsec). This has stimulated the development of new concepts for imaging instruments: on one side, the focusing telescopes like γ-ray lens, using small,well shielded detector volumes, on the other side very large area γ-ray imagers, both allowing a big step in sensitivity. We report on a study for the concept of a large area (1 square meter), narrow field coded mask telescope with arcsec imaging capability, based on CZT detector technology and active collimation system, made of Si microstrip detector modules and operating in the energy band 15-500 keV. Feasibility and performance characteristics are discussed as well as possible geometric configurations and background suppression schemes, in the light of data obtained from INTEGRAL/IBIS and other CdTe/CZT instruments currently in space.

The solar powered sail spacecraft using a huge sail is a next Japanese engineering verification satellite planned to launch in 2012. It has a hybrid propulsion system with ion engines and a huge solar sail panel of 50 m in diameter. Based on the present mission plan, it will take about 6 years to cruise to Jupiter via Earth swing-bys and 5 more years to reach the Jovian L4 Trojan asteroids. During its cruising phase, we plan to mount a gamma-ray burst (GRB) detector with polarization detection capability which also works as one of the interplanetary network (IPN) to determine the GRB positions. The emission mechanism of GRB is thought to be the synchrotron radiation from the relativistic outflows. If the emission mechanism of GRBs is really synchrotron radiation, the emitted gamma-rays should be strongly polarized. The detection principle is the anisotropy of the Compton scattering. The Compton-scattered gamma-ray photons show the strongly biased distribution toward the vertical direction against the oscillating electric field vector. The design concept of our detector is simple but carefully avoid a fake modulation. The plastic scintillator in one Compton-length as the scattering body is placed at the center, and 12 CsI scintillators are allocated around it. To avoid a fake modulation through the satellite body scattering, these detectors work in coincidence mode. The coincidence also helps to reduce the particle background. We will use the VA-TA ASIC and FPGA as the analog readout and the digital event processing, respectively, to make the detector weight of almost 2.0 kg. In this paper, we introduce the solar sail mission and show the overview of gamma-ray polarimeter.

A Laue lens gamma-ray telescope represents an exciting concept for a future high-energy mission. The feasibility of such a lens has been demonstrated by the CLAIRE lens prototype; since then various mission concepts featuring a Laue lens are being developed. The latest, which is also the most ambitious, is the European Gamma-Ray Imager (GRI). However, advancing from the CLAIRE prototype to a scientifically exploitable Laue lens requires still substantial research and development. First and foremost, diffracting elements (crystals) that constitute the Laue lens have to be optimized to offer the best efficiency and imaging capabilities for the resulting telescope. The characteristics of selected candidate crystals were measured at the European Synchrotron Radiation Facility on the high-energy beamline ID 15A using a beam tuned at 292 keV. The studied low mosaicity copper crystals have shown absolute reflectivity reaching 30%. These crystals are promising for the realization of a Laue lens, despite the fact that they produce a diffracted beam featuring a Gaussian intensity profile, which contributes to the spread of the focal spot. A composition gradient Si_1-x-Ge_x crystal has been investigated as well, which showed a diffraction efficiency reaching 50% (disregarding absorption) - half of the theoretical maximum - that represents an absolute reflectivity around 39 %, the best that we measured at this energy to date. This gradient crystal also showed a square-shaped rocking curve that is almost the best case to minimize the spread of the focal spot. We also show that bending a gradient crystal could still enhance the focusing. Thanks to the better focusing, a factor of 2 in sensitivity improvement may be achieved.

Astronomical surveys have demonstrated an enormous capability for increasing our understanding of the universe around us. There are significant wavelength regions, which for various reasons are poorly sampled. Powerful diagnostics of hot gas in the universe are well understood, but there are few instruments capable of making measurements at the wavelengths of the most important lines (103 nm, 123 nm, and 155 nm, the lithium-like series of O, N, and C). No complete survey has been done with moderate spatial resolution in emission even though virtually all measurements capable of detecting the presence of lithium-like oxygen do so. We present a technique to eliminate the spectral-spatial confusion inherent in a wide field imaging spectrograph based on a type of imaging spectrograph that takes advantage of the large, well-corrected field of view from a three-mirror anastigmat (TMA) in conjunction with aberration-corrected holography applied to the tertiary.

The study of the Sun in the UV spectral domain is essential for a better understanding of the physical processes taking place in the solar atmosphere. The main tools for this study are imagers and spectrometers. Nevertheless, the analysis of imagery data is rapidly limited unless spectral information is available, and the association of spectrometers and imagers is limited by the lack of coherence between the instruments. Therefore, the design of an imaging spectrometer in UV is a priority for solar physicists. In the far UV, only all reflective optical systems can be used thus an imaging Fourier transform spectrometer (IFTS) is the ideal candidate for the realization of such an instrument. The performances of an IFTS are given by the modulation efficiency. Theoretical study of performances and scientific objectives lead to technical and operating specifications. A mock-up of an IFTSUV has been built at IAS to validate the working principle. Its optical design and alignment are described in this paper. The first results are shown and discussed. Planned modifications of the design are also discussed.

The hard X-ray imager (HXI) is the primary detector of the NeXT mission, proposed to explore high-energy non-thermal phenomena in the universe. Combined with a novel hard X-ray mirror optics, the HXI is designed to provide better than arc-minutes imaging capability with 1 keV level spectroscopy, and more than 30 times higher sensitivity compared with any existing hard X-ray instruments. The base-line design of the HXI is improving to secure high sensitivity. The key is to reduce the detector background as far as possible. Based on the experience of the Suzaku satellite launched in July 2005, the current design has a well-type tight active shield and multi layered, multi material imaging detector made of Si and CdTe. Technology has been under development for a few years so that we have reached the level where a basic detector performance is satisfied. Design tuning to further improve the sensitivity and reliability is on-going.

We give overview and the current status of the development of the Soft X-ray Imager (SXI) onboard the NeXT satellite. SXI is an X-ray CCD camera placed at the focal plane detector of the Soft X-ray Telescopes for Imaging (SXT-I) onboard NeXT. The pixel size and the format of the CCD is 24 x 24μm (IA) and 2048 x 2048 x 2 (IA+FS). Currently, we have been developing two types of CCD as candidates for SXI, in parallel. The one is front illumination type CCD with moderate thickness of the depletion layer (70 ~ 100μm) as a baseline plan. The other one is the goal plan, in which we develop back illumination type CCD with a thick depletion layer (200 ~ 300μm). For the baseline plan, we successfully developed the proto model 'CCD-NeXT1' with the pixel size of 12μm x 12μm and the CCD size of 24mm x 48mm. The depletion layer of the CCD has reached 75 ~ 85μm. The goal plan is realized by introduction of a new type of CCD 'P-channel CCD', which collects holes in stead of electrons in the common 'N-channel CCD'. By processing a test model of P-channel CCD we have confirmed high quantum efficiency above 10 keV with an equivalent depletion layer of 300μm. A back illumination type of P-channel CCD with a depletion layer of 200μm with aluminum coating for optical blocking has been also successfully developed. We have been also developing a thermo-electric cooler (TEC) with the function of the mechanically support of the CCD wafer without standoff insulators, for the purpose of the reduction of thermal input to the CCD through the standoff insulators. We have been considering the sensor housing and the onboard electronics for the CCD clocking, readout and digital processing of the frame date.

The hard X-ray detector (HXD) onboard Suzaku covers an energy range of 8-700 keV, and thus in combination with the CCD camera (XIS) gives us an opportunity of wide-band X-ray observations of celestial sources with a good sensitivity over the 0.3-700 keV range. All of 64 Si-PIN photo diodes, 16 GSO/BGO phoswich scintillators, and 20 anti-coincidence BGO scintillators in the HXD are working well since the Suzaku launch on July 2005. The rejection of background events is confirmed to be as effective as expected, and accordingly the HXD achieved the lowest background level of the previously or currently operational missions sensitive in the comparable energy range. The energy and angular responses and timing have been continuously calibrated by the data from the Crab nebula, X-ray pulsars, and other sources, and at present several % accuracy is obtained. Even though the HXD does not perform simultaneous background observations, it detected weak sources with a flux as low as ~0.5 mCrab; stars, X-ray binaries, supernova remnants, active galactic nuclei, and galaxy clusters. Extensive studies of background subtraction enables us to study weaker sources.

A program for developing TES microcalorimeters for contributions to future Italian X-ray astronomy missions is under course. Its main scientific goals are the spectroscopic study of extreme astrophysical objects, characterized by very large energy release over short time scale, in particular gamma-ray bursts and transient compact objects, and the study of the early and close-by Universe by using gamma-ray bursts as cosmological beacons. Presently, the energy resolution of our detector has been improved to about 6 eV at 6 keV, with rise-time of about 10 μs and fall time of few hundreds of μs. We are developing and studying the suitable absorbers for high count rate performances.

The next Japanese X-ray astronomical satellite mission, NeXT, was proposed to ISAS/JAXA following the Astro-E2 Suzaku satellite which was launched in July 2005. We develop an X-ray CCD camera system, SXI (Soft X-ray Imager), for NeXT. The Hard X-ray Telescope (HXT) onboard NeXT provides imaging capability up to 80 keV, using the multilayer-coated X-ray mirror technology, called "Supermirror", newly developed in Japan. SXI is one of the focal plane detectors of HXT, which covers the soft energy band in the 0.5-12 keV in the baseline and 0.3-25 keV in the goal. We develop p-type CCDs for the baseline of SXI because p-type CCDs have been successfully used for previous X-ray astronomical satellites. We developed a prototype of a p-type CCD for SXI, called "CCD-NeXT1". CCD-NeXT1 is a frame-transfer CCD with two readout nodes. The image area of CCD-NeXT1 consists of 2Kx2K pixels with a pixel size of 12 μm x 12 μm. We evaluated performance of CCD-NeXT1 devices, KG-4 and KG-5. The energy resolution was 141.8±0.6 eV full width at half maximum at 5.9 keV, the readout noise was 4.7±0.2 e^-, the horizontal CTI was < 5.1 x 10^-7, and the vertical CTI was < 2.4 x 10^-7 for KG-5. The performance of KG-4 was more or less the same as that of KG-5. The thickness of the depletion layer was 82±7 μm for KG-4 and 76±6 μm for KG-5. We conclude that our technology for p-type CCDs is sufficient to satisfy the CCD performance for the baseline of SXI.

Simbol-X is a next generation X-ray telescope with spectro-imaging capabilities over the 0.5 to 80 keV energy range. The combination of a formation flying mirror and detector spacecraft allows to extend the focal length to 20 m, resulting in a so far unrivaled angular resolution and sensitivity in the hard X-ray range. The focal plane detector system for Simbol-X is planned to consist of an array of so-called Macro Pixel Detectors (MPD) on top of a 2 mm thick CdZnTe pixellated detector array. Photons of energy less than about 17 keV will be primarily absorbed in the MPDs, whereas higher energy photons will be detected in the CdZnTe array below. A computer model of such stacked detectors and its interaction with the radiation environment encountered by the spacecraft in orbit is currently being developed by our group using the Monte Carlo toolkit GEANT4. We present results of the simulation and an outlook for possible optimizations of future detector geometry and shielding.

We report laboratory measurements of the response of a back-illuminated, X-ray photon-counting charge-coupled device at X-ray energies between 80 and 500 eV. The detector tested, which is similar to one currently in orbit aboard the Suzaku X-ray Imaging Spectrometer, has been treated with the chemisorption charging process developed by Lesser and colleagues. We report energy scale linearity and spectral resolution measurements in this energy band, which spans the silicon L_II,III absorption edge, and demonstrate useful spectral resolution at energies as low as 83 eV with our single-read-per-pixel system. We discuss the factors currently limiting device performance and briefly consider the challenges of exploiting this capability in future astronomical instruments.

The flight calibration of the spectral response of CCD instruments below 1.5 keV is difficult in general because of the lack of strong lines in the on-board calibration sources typically used and the relatively poor spectral resolution at the lowest energies. We used 1E 0102.2-7219 (the brightest supernova remnant in the SMC) to evaluate the response models of the ACIS CCDs on the Chandra X-ray Observatory and the EPIC CCDs on the XMM-Newton Observatory. E0102 has strong lines of O, Ne, and Mg below 1.5 keV and very little or no Fe emission to complicate the spectrum. The spectrum of E0102 has been well-characterized using the gratings on the CXO and XMM-Newton. We have used the high-resolution spectral data from both gratings instruments to develop a spectral model for the CCD spectra. Fits with this model are sensitive to any problems with the gain calibration and the spectral redistribution model. We have also used the measured intensities of the lines to investigate the consistency of the detection efficiency models for the different instruments. We find that the gain of the three instruments is accurate to within 1.1% at ~ 570 eV and 0.9% at ~ 910 eV. We find that the measured flux of the Ne X Ly α line agrees at the 90% confidence limit for all detectors (within 6%). We find significant differences in the measured flux of the O VIII Ly α line, the largest discrepancy between one pair of datasets is 18%. Further analysis is required to investigate this discrepancy.

We report on a new photon-counting detector possessing unprecedented spatial resolution and moderate spectral resolution for 0.5-100keV X-rays. It consists of an X-ray charge-coupled device (CCD) and a scintillator. The scintillator is directly coupled to the back surface of the X-ray CCD. Low-energy X-rays below 10keV can be directly detected by the CCD. The majority of hard X-rays above 10keV pass through the CCD but can be absorbed by the scintillator, generating visible photons. We employ the needlelike CsI(Tl) in order to prevent the lateral spread of visible photons. We performed the Monte Carlo simulation with DETECT2000 both to maximize the number of visible photons detected by the CCD and to minimize the lateral spread of visible photons on the CCD. We then fabricated the optimized needlelike CsI(Tl) with 300 μm thick and coupled it on the front surface of the back-illuminated (BI) CCD. The high detection efficiency of BI CCDs in the visible band enables us to collect visible photons emitted from the CsI(Tl) efficiently, leading to the moderate spectral resolution of 30% at 59.5keV combined with the high detection efficiency for hard X-rays. We plan to perform the hard X-ray imaging balloon-borne experiment, SUMIT, in autumn of 2006 at Brazil. We also describe the details about the balloon system of the SD-CCD.

We discuss a new class of Micro Pattern Gas Detectors, the Gas Pixel Detector (GPD), in which a complete integration between the gas amplification structure and the read-out electronics has been reached. An Application-Specific Integrated Circuit (ASIC) built in deep sub-micron technology has been developed to realize a monolithic device that is, at the same time, the pixelized charge collecting electrode and the amplifying, shaping and charge measuring front-end electronics. The CMOS chip has the top metal layer patterned in a matrix of 80 μm pitch hexagonal pixels, each of them directly connected to the underneath electronics chain which has been realized in the remaining five layers of the 0.35 μm VLSI technology. Results from tests of a first prototype of such detector with 2k pixels and a full scale version with 22k pixels are presented. The application of this device for Astronomical X-Ray Polarimetry is discussed. The experimental detector response to polarized and unpolarized X-ray radiation is shown. Results from a full MonteCarlo simulation for two astronomical sources, the Crab Nebula and the Hercules X1, are also reported.

We report a new type X-ray imaging polarimeter: a multilayer-coated CCD. When the X-rays are detected by the CCD, with the incident angle of 45 deg, through the coated multi-layer, the transmissions of the P and S polarized photons are different from each other and we can get an image with a selected position angle of the polarization. By the simulation of the transmission of the multi-layer, we designed an optimal number of the layer-pair and their thickness. The target wave length is 135Å, because the Mo/Si multi-layer has a good performance in this energy range. If the dead layer of the back-side CCD is 1000Å, nine layer-pairs make the largest difference between the P and S transmission. We deposited the Mo/Si multi-layer directly on a back-side CCD. The CCD was exposed to the polarized photons from synchrotron radiation with 45 deg incident angle. The detected intensity is measured as a function of the photon energy and of the rotation angle around the photon beam. The detection of the polarization is confirmed. However the measured performance is lower than expected. Some possibilities of the cause are discussed.

The polarization data in hard X-ray and gamma-ray energy regimes remain until now very scarce. Having in mind very large importance of the polarization information provided by astrophysical objects we propose a novel compact polarimeter POLAR. It utilizes Compton scattering process and is based on the detector array made of low-Z, fast scintillators. As the instrument with its relatively small dimensions and mass will be a non-intrusive one, it can be installed on any typical satellite platform. It has a sensitivity peak in the energy range from tens to several hundreds keV and a wide viewing angle covering almost a third of the sky. The main objects to be observed by POLAR will be Gamma Ray Bursts and X-Ray Flashes but also X-ray pulsars (Crab). The instrument response and measurement accuracy were intensively modeled and optimized in series of Monte Carlo simulations. It resulted in laboratory design that consists of 2304 plastic scintillator bars with dimension 6x6x200 mm³. The scintillator light is converted by an array of multi-anode photomultipliers. This arrangement assures both a large effective area for Compton scattering as well as a big polarization modulation factor. Moreover, both quantities keep large values also for gammas coming off the detector axis. Currently, a sequence of laboratory tests is performed using polarized photon sources of different energies and various experimental setups. The first experiment consists of small (8x8) array of nominal scintillators while the other one will utilize a large array (1536) of smaller bars (4x4x20 mm³) from the existing high energy project. The goal of these two measurements is to optimize the design, validate simulation results and test the prototype.

Development of multi-layer optics makes feasible the use of X-ray telescope at energy up to 60-80 keV: in this paper we discuss the extension of photoelectric polarimeter based on Micro Pattern Gas Chamber to high energy X-rays. We calculated the sensitivity with Neon and Argon based mixtures at high pressure with thick absorption gap: placing the MPGC at focus of a next generation multi-layer optics, galatic and extragalactic X-ray polarimetry can be done up till 30 keV.

We report on the origin of the instrumental background of the X-ray CCD camera in space obtained from the Monte Carlo simulation with GEANT4. In the space environment, CCD detects many non-X-ray events, which are produced by the interactions of high-energy particles with the materials surrounding CCD. Most of these events are rejected through the analysis of the charge split pattern, but some are remained to be background. Such instrumental background need to be reduced to achieve higher sensitivity especially above several keV. We simulated the interactions of the cosmic-rays with the CCD housing, and extracted the background events which escaped from the screening process by the charge split pattern. We could reproduce the observed spectral shape of the instrumental background of Suzaku XIS on orbit with the Monte Carlo simulation. This means that the simulation succeeded to duplicate the background production process in space. From the simulation, we found that the major components of the background in the front-side illuminated CCD are the recoil electrons produced by the Compton-scattering of the hard X-ray photons in the CCD. On the other hand, for the backside illuminated CCD, contribution from the low energy electrons becomes dominant, which are produced by the interactions of cosmic-ray protons or hard X-rays with the housing. These results may be important to design the X-ray CCD camera for the future missions, such as NeXT.

We report on the technical and scientific performance of JEM-X, the X-ray monitor on ESA's INTEGRAL mission. INTEGRAL has now been in orbit for more than three years, and the mission is foreseen to be extended until the end of 2010. Overall, JEM-X performs very well, and can be expected to continue to do so for the duration of the mission. We discuss in some detail the operational experiences and the problems encountered with the microstrip detectors caused by the space environment and give one example of the interesting scientific results obtained. The analysis software is still being improved on, and we discuss briefly the significance of these improvements.

The XMM-Newton observatory is collecting a tremendous amount of X-ray imaging spectroscopy data. To deal with this huge volume of data, we are investigating more efficient methods to classify astronomical sources based purely on their X-ray spectra, and to understand the fundamental physical mechanisms responsible for X-ray emission. Multivariate statistics and pattern classification techniques are powerful tools to provide insight into the spectral similarities between a given target and its neighbors in the same observation. With this goal, we are developing approaches to classification of X-ray CCD spectra obtained by the XMM EPIC CCD instruments. Although X-ray CCD spectra have low resolution, they can be obtained in batches, whereas a high resolution spectrum can be only generated by the XMM RGS spectrometer for the brightest sources. Furthermore, X-ray CCD spectra can yield the relationship, if any, between the target source and other sources in the same field. The initial results are demonstrated by using a field centered on V1647 Ori, a young star that has recently displayed an accretion-driven optical, infrared and X-ray outburst. We applied Principle Component Analysis (PCA) to reduce the data dimensionality and Independent Component Analysis (ICA) to separate the CCD spectra as independently as possible. Then the Hierarchical Clustering classification method was employed to discriminate between this eruptive young star and other pre-main sequence X-ray sources in the field.

SuperAGILE is the hard X-ray (15-45 keV) imager for the gamma-ray mission AGILE, currently scheduled for launch in early 2007. It is based on 4 Si-microstrip detectors, with a total geometric area of 1444 cm² (max effective area 230 cm²), equipped with 4 one-dimensional coded masks. The 4 detectors are perpendicularly oriented, in order to provide pairs of orthogonal one-dimensional images of the X-ray sky. The field of view of each 1-D detector is 107° x 68°, at zero response, with an overlap in the central 68° x 68° area. The angular resolution on axis is 6 arcmin. We present here the current status of the hardware development and the scientific perspective.

We present a satellite mission concept to measure the dark energy equation of state parameter ω with percent-level precision. The Very Ambitious Dark Energy Research satellite (VADER) is a multi-wavelength survey mission joining X-ray, optical, and IR instruments for a simultaneous spectral coverage from 4 μm (0.3 eV) to 10 keV over a field of view (FoV) of 1 square degree. VADER combines several clean methods for dark energy studies, the baryonic acoustic oscillations in the galaxy and galaxy cluster power spectrum and weak lensing, for a joint analysis over an unrivalled survey volume. The payload consists of two XMM-like X-ray telescopes with an effective area of 2,800 cm² at 1.5 keV and state-of-the-art wide field DEPFET pixel detectors (0.1-10 keV) in a curved focal plane configuration to extend the FoV. The X-ray telescopes are complemented by a 1.5m optical/IR telescope with 8 instruments for simultaneous coverage of the same FoV from 0.3μm to 4μm. The 8 dichroic-separated bands (u,g,r,z,J,H,K,L) provide accurate photometric galaxy redshifts, whereas the diffraction-limited resolution of the central z-band allows precise shape measurements for cosmic shear analysis. The 5 year VADER survey will cover a contiguous sky area of 3,500 square degrees to a depth of z~2 and will yield accurate photometric redshifts and multi-wavelength object parameters for about 175,000 galaxy clusters, one billion galaxies, and 5 million AGN. VADER will not only provide unprecedented constraints on the nature of dark energy, but will additionally extend and trigger a multitude of cosmic evolution studies to very large (>10 Gyrs) look-back times.

We outline a novel satellite mission concept, DEMON, aimed at advancing our comprehension of both dark matter and dark energy, taking full advantage of two complementary methods: weak lensing and the statistics of galaxy clusters. We intend to carry out a 5000 deg² combined IR, optical and X-ray survey with galaxies up to a redshift of z~2 in order to determine the shear correlation function. We will also find ~100000 galaxy clusters, making it the largest survey of this type to date. The DEMON spacecraft will comprise one IR/optical and eight X-ray telescopes, coupled to multiple cameras operating at different frequency bands. To a great extent, the technology employed has already been partially tested on ongoing missions, therefore ensuring improved reliability.

We present a concept study for a novel All Sky Monitor experiment employing very limited resources. Our experience in designing, building and testing SuperAGILE - the hard X-ray imager for the AGILE mission - has demonstrated the possibility to develop a medium-sensitivity, wide field imager, with (at launch stage) ~5.5 kg weight, 12 Watts power and 0.04 cubic meters volume. With these few resources, it can provide crossed one-dimensional images of 1/10^th of the sky, with on-axis 6 arcminutes angular resolution and ~10 mCrab 1-day sensitivity in the 15-45 keV energy range. In this paper we introduce to the ASPEX (All Sky Project for Extraterrestrial X-rays) project and show how a much more efficient All Sky Monitor can now be designed using the same approach and techniques, overcoming a number of severe limitations suffered by SuperAGILE due to the context of the AGILE mission, for which it was designed. The low resources and its efficiency in localizing X-ray transients and in long-term monitoring the steady X-ray sky, make ASPEX a suitable option for several new mission concepts (e.g., PHAROS, ESTREMO, ...).

The Flight Model of the SuperAGILE experiment was calibrated on-ground using an X-ray generator and individual radioactive sources at IASF Rome on August 2005. Here we describe the set-up, the measurements and the preliminary results of the calibration session carried out with the X-ray generator. The calibration with omnidirectional radioactive sources are reported elsewhere. The beam was collimated using a two slits system in order to reach a rectangular spot at the detector approximately 1800 μm × 100 μm in size. The long dimension was aligned with the detector strip, so that the short dimension could fall within one single detector strip (121 μm wide). The detector was then slowly moved continuously such that the beam effectively scanned along the coding direction. This measurement was done both at detection plane level (i.e., without collimator and mask) to characterize the detector response, and at experiment level (i.e., with collimator, mask and digital electronics), to study the imaging response. Aim of this calibration is the measurement of the imaging response at 0, 10 and 20 degrees off-axis, with a parallel beam, although spatially limited to a ~2 mm long section of the coded mask.

The Flight model of SuperAGILE experiment was calibrated on-ground on August 2005 at IASF-Rome laboratories using standard radioactive X-rays sources. These omnidirectional sources were positioned at approximately 2 meters distance from the experiment. A method to correct for the beam divergence has been developed in order to use these measurements to derive information about the point spread function of the experiment for infinite distance sources. In this paper we describe the set-up of the measurements, the method to correct for the beam divergence and show preliminary results of the data analysis.

We discuss and analyze a two reflection grazing incidence spectrograph concept based on the Kirkpatrick-Baez telescope. The classical Kirkpatrick-Baez telescope uses two banks of crossed, cylindrical mirrors to achieve focus. Performance of a two reflection design is discussed for single mirror set and multiple mirror bank configurations.

The Space Telescope European Co-ordinating Facility (ST-ECF) and National Institute of Standards and Technology (NIST) are collaborating to study hollow cathode calibration lamps as used onboard the Hubble Space Telescope (HST). As part of the STIS Calibration Enhancement (STIS-CE) Project we are trying to improve our understanding of the performance of hollow cathode lamps and the physical processes involved in their long term operation. The original flight lamps from the Faint Object Spectrograph (FOS) and the Goddard High Resolution Spectrograph (GHRS) are the only lamps that have ever been returned to Earth after extended operation in space. We have taken spectra of all four lamps using NIST's 10.7-m normal-incidence spectrograph and Fourier transform spectrometer (FTS) optimized for use in the ultraviolet (UV). These spectra, together with spectra archived from six years of on-orbit operations and pre-launch spectra, provide a unique data set--covering a period of about 20 years--for studying aging effects in these lamps. Our findings represent important lessons for the choice and design of calibration sources and their operation in future UV and optical spectrographs in space. Our results will be directly used for planning science operations of the Cosmic Origins Spectrograph (COS) which is going to be installed on the HST during the next servicing mission.

X-ray optics based on pore geometries have opened applications for X-ray telescopes in the planetary and astrophysics areas where very restricted resources are allowed. In this paper the mission design for a limited size X-ray telescope is presented, which is based on a stowed structure to be deployed in a L2 orbit. With the application of silicon based pore optics in the conical approximation of the Wolter geometry [1, 2, 3] an appreciable effective area can be achieved at 1keV. The energy response function can be extended and optimised towards higher energies by the application of more complex reflective coatings including multiplayer designs [4, 5]. The angular resolution is kept compatible with this collecting area, avoiding source confusion. One of the workhorse launchers for the ESA science missions, the Soyuz Fregat, is assumed as vehicle. The main trade-offs of the mission design will be addressed and the performance of such a telescope is discussed.

Imaging observation in the hard X-ray band of 10 - 100 keV is one of the important subjects in X-ray astronomy. Though SUMIT balloon-borne experiment, we have developed thin-foil-nested hard X-ray telescope employing depth-graded Pt/C multilayer (multilayer-supermirror). We have improved production process of the replica reflector and telescope optics compared with InFOCμS-2004 telescope. The new telescope was measured at synchrotron radiation facility, SPring-8. The image quality and throughtput were estimated to be 2.06 arcmin (half power diameter) and 85 % at 30 keV, respectively. These values were about 24 % and 30 % improvement compared to InFOCμS-2004, respectively. Limiting factors of its performance are also investigated. Based on such an investigation we are now continuously developing hard X-ray telescope for SUMIT 2006 flight.

Detailed measurements of reflectivity of gold, which is used for X-ray mirror for X-ray telescope onboard "Suzaku" satellite was performed in the synchrotron radiation facility SPring-8 BL15XU. We measured reflectivity of the mirror, which uses total reflection of gold thin layer. Grazing incidence angle is 0.5 degree and incident X-ray monochromatized in the energy range from 2.2 keV to 3.5 keV, where M-edge structure of gold appears. We used double crystal monochrometer using Si(111) crystal, (ΔE/E ~ 10^-4) to monochromatize the incident X-ray. Energy calibration was performed using L-edge of molybdenum (2530.2 eV) and K-edge of argon (3205.9 eV). From the results, that the energy of M-V and M-IV edge of gold is different from optical constant table, and almost same as the value reported by Graessle et al.(1992).¹ It is important to study the optical constants of gold or other mirror material for X-ray astronomy. This results will be feed back to the response function of the X-ray telescope of Suzaku satellite. It is very important for X-ray spectroscopy in X-ray astronomy.

Dealing with very large size optics for the next generation of X-ray telescopes, like XEUS or ConX/SXT, it's necessary to build segmented mirrors which are assembled in petals because it's impossible to realize them in a monolithic form. The shape of these petals can be square or circular. The main problem is that such optics must have a very low weight compared to past X-ray telescopes, but assuring optimal imaging capabilities. In this paper I compare two different techniques that can achieve this so low weight. One is known as High Precision pore Optics (HPO) and the other one is based on a more classical shaped segments, assembled together, but built with very thin (in the 100-300 μm range) glass sheets that are stiffened with ribs. In this study, the main geometrical differences between the two approaches assumed, is that the first one has a pore size that doesn't change along the optics radius while the second one is based on a constant length. The main purpose of this study is to understand when one concept can be better than the other, depending on a given set of parameters, such as the focal length of the telescope, the filling factor of optic, the thickness of the walls, the radius of the segment, etc. The final goal is to achieve the best optimization of the mass to area ratio.

The X-ray Astronomy Calibration and Testing (XACT) facility of the Instituto Nazionale di Astrofisica (INAF) at Osservatorio Astronomico di Palermo has recently undergone a major upgrade with the design and construction of a 35 meter long vacuum beam-line operating in the soft X-rays (0.1-20 keV) and the addition of new hardware to meet the requirements for testing and calibration of next generation X-ray missions. We report on the present configuration of the facility and briefly survey the range of its applications.

We describe a "built in house" X-ray monochromator which produces a fixed exit X-ray beam tunable in the full energy range 0.1 - 20 keV. The system is based on a double diffraction on two large size parallel crystals positioned using a remotely controlled micropositioning system in order to keep the position of the monochromatic beam for any chosen energy. Up to six different diffracting elements can be selected without breaking the vacuum. This allows to cover the full energy range of interest. The system is part of an upgrading project of the XACT facility at the Istituto Nazionale di Astrofisica - Osservatorio Astronomico di Palermo G.S. Vaiana, and will be employed for the testing and calibration of filters, detectors and optics at X-ray wavelengths.

The PANTER X-ray Test Facility was originally designed to support the development and construction of the ROSAT mirror system. A large instrument chamber (length 12 m, diameter 3.5m) accommodates the optics to be analysed. The X-ray sources covering an 0.2 - 50 keV energy range are located at a distance of 123m from the entrance to the chamber to provide an almost parallel X-ray beam. Both are connected by a vacuum tube of 1m diameter. In addition to ROSAT a large number of astronomical systems like telescopes for Exosat, BeppoSAX, JET-X, ABRIXAS, XMM-Newton and Swift - but also gratings (e.g., LETG on Chandra), filters, and focal plane detectors have been measured at the facility. As a "growing facility" we are currently planning to apply changes to the facility layout to support measurements of instrumentation for future missions like XEUS. Currently a parallel beam is set up using a spare CDS mirror ("Coronal Diagnostic Spectrometer", for the SOHO mission) as condensor. Moreover, extensions to vacuum tube and instrument chamber are under consideration, both to allow calibration of systems with focal lengths significantly longer than XMM-Newton. A new focal plane camera using a CCD developed for the eROSITA mission will improve spatial and spectral resolution. Finally, the energy coverage shall be extended to lower and to higher energies. Already with the present configuration important issues like performance under low temperatures could be investigated.

We report a useful visible light testing procedure for a first analysis of soft X-ray grazing incidence optics (0.1-2 keV). Although diffraction is a limit in the application of this method, great advantages are obtained by running the tests in air with direct access to modify the geometrical mounting of the individual mirror shells. We present the experimental apparatus and show the first results of the investigation of light weight optics based on plastic foil material and comparison with results obtained with an X-ray beam.

Presented are results of a fabrication program to produce the Ring Imaging Cherenkov, RICH, mirror for the Alpha Magnetic Spectrometer, AMS-02, which is to be placed on the International Space Station. Composite Mirror Applications, Inc., CMA, in Tucson AZ was contracted by Carlo Gavazzi Space, CGS, to produce a conical mirror 1.3m diameter 0.5m in height, from high modulus carbon fiber, flight qualified composite materials, having an optical surface on the inside of the cone. The flight model mirror was completed to specification, yielding nearly 2m² of replicated optical surface area and weighs 8 kg. CMA measured the surface roughness and slope errors and the mirror dimensions were measured using a CMM at The University of Arizona's Instrument Shop. The results show the mirror meets conformance to the required specifications. The RICH mirror is currently undergoing flight testing and integration.

CCD detectors in the focal plane cameras of grazing incidence X-ray telescopes on the XMM-Newton and SWIFT satellites have encountered damage which has been attributed to impacts by external particles. The apparent mechanism is one whereby interplanetary micrometeoroid particles or space debris have been ingested by the grazing incidence mirrors and scattered down the telescope tube on to the CCD detectors in the focal plane. At the time of writing, there have been 5 such events detected in total by the three XMM telescopes during five years of operations and one event detected by the SWIFT X-ray Telescope (XRT) during one year in orbit. Significantly, no events of this type have been reported for Chandra. Modelling and analysis of scattering of small particles from grazing incidence mirrors allows us to explain the different impact rates seen by these three satellites. Furthermore, using the ESA MASTER2005 micrometeoroid and space debris impacts flux model, impact rates have been derived from consideration of Swift's orbit, pointing history and the dust and debris particle environment. This modelling can be used to determine whether risk mitigation strategies are required for the continuing operation of SWIFT and other operating observatories, and also provides a basis for predicting particle impact rates for grazing incidence telescopes on future missions such as XEUS, Constellation-X and others.

Hard X-ray concentrators based on glass poly-capillary lenses (Kumakhov optics) can bring new flavor for the next generation of astrophysical instruments. We discuss the advantage of such a concentrator for missions such as new Spectrum-X-Gamma, for both scanning and pointing observational modes. Even though an X-ray concentrator has no true imaging capabilities and therefore can not compete with grazing incident mirror instruments, it could be quite useful. For pointing observations the instrument with large area poly-capillary glass concentrator combined with small CZT detector sensitive in the 5-80 keV energy range would significantly improve the faint point sources spectroscopy in hard X-rays. This is of particular interest due to recent INTEGRAL and Swift discovery of the large number of obscured AGNs and comparison of their spectra with the spectrum of the cosmic hard X-ray background. The other important areas to be explored are detection of the Ti-44 line in the supernova remnants and detailed study of high-energy hyrolines in the spectra of X-ray pulsars. The expected parameters of the instrument show that it could be an order of magnitude more sensitive compared to standard coded aperture telescopes. We also explore the potentials of the X-ray concentrator in the scanning mode during the survey phase of the mission.

Diffraction gratings used in space telescopes are desired to provide high diffraction efficiency and large collecting area while maintaining minimal mass to meet cost limitations. As a result, the method of assembling such gratings into modules such that all requirements are met becomes critical. We report on the development of a new assembly scheme that densely stacks thin reflection grating substrates using precision spacers. A custom-designed, optically-polished vacuum chuck is used to constrain the substrates for grating surface metrology during assembly. This rigid subassembly composed of the vacuum chuck and grating is manipulated in space until the grating surface final angular and lateral positions are obtained, at which point the grating is transported from the chuck onto the spacers and glued in that final position. This method not only precisely aligns the gratings with respect to each other, but also improves the overall surface flatness of the substrates, since they are constrained by a flat vacuum chuck within the assembly process. This helps reduce the tolerances on the substrate shaping methods followed prior to assembly.

The DEPMOSFET (Depleted p-channel MOSFET) is an Active Pixel Sensor (APS) for the XEUS Wide Field Imager (WFI), which is developed and produced by the MPI semiconductor laboratory in Munich (HLL). The current prototype detector consists of a hybrid where a 64 x 64 pixel matrix with 75 μm x 75 μm pixel size each is mounted together with CMOS SWITCHER II ICs for row-selection and a CAMEX 64 ASIC for readout. First measurements for this device have shown the high energy resolution and quantum efficiency as well as the potential for fast readout. For fast timing studies on XEUS an instrument is needed which is able to deal with count rates up to 10⁶ photons s^-1 with 10 μs time resolution. At the Institut fuer Astronomie und Astrophysik, we have built a setup to investigate the timing performance of the current prototype detector and to study the capability of the DEPMOSFET detector to handle high count rates. In this paper we present the Data Acquisition System and the future plans for this setup.

AGILE is a small space mission of the Italian Space Agency (ASI) devoted to astrophysics in the gamma-ray energy range 30 MeV - 50 GeV, and in the X-ray band 15 keV - 45 keV. The AGILE Payload is composed of three instruments: a gamma-ray imager based on a Tungsten-Silicon Tracker (ST), for observations in the gamma ray energy range 30 MeV - 50 GeV, a Silicon based X-ray detector, Super-Agile (SA), for imaging in the range 15 keV - 40 keV and a CsI(Tl) Mini-Calorimeter (MCAL) that detects gamma rays or particle energy deposits between 300 keV and 200 MeV. The payload is currently fully integrated and the satellite is expected to be launched in the second half of 2006. MCAL is composed of 30 CsI(Tl) scintillator detectors with the shape of a bar with photodiode readout at both ends, arranged in two orthogonal layers. MCAL can work both as a slave of the ST and as an independent gamma-ray detector for the detection of transients and Gamma Ray Bursts. In this paper a detailed description of MCAL is presented together with the first on ground calibration results.

We have been developing position sensitive scintillation counter as focal plane detector of hard X-ray telescope onboard a balloon borne experiment. This detector consists NaI(TI) scintillator and position sensitive photo-multiplier tube. Focal plane detector has to have high efficiency in hard X-ray region, enough position resolution and detection area. 3mm thickness of NaI(TI) scintillator can achieve almost 100% efficiency below 80 keV. We measured position resolved energy and position resolution in synchrotron radiation facility SPring-8 BL20B2. Position resolution of 2.4mm at 60keV is about half of plate scale of half power diameter of X-ray telescope. The detector has 6 cm diameter window and it corresponds to 25 arcmin field of view, and it is enough lager than the that of telescope, which is 12 arcmin in FWHM. Balloon borne experiment for observation of the background was performed on May 24, 2005 from Sanriku balloon center. We could obtain background data for 3 hours at altitude of 40 km.

Since its launch in 1999, the European X-ray observatory XMM-Newton has suffered, 4 times, possible micro-meteoroid impacts believed to occur in the mirror shells, scattering debris toward the focal plane. The latest event, on 2005 March 09^th, caused the loss of EPIC MOS1 CCD6, as well as small damage to MOS1 CCD1. This latter defect is leaking into the whole column that passes a few pixels from the nominal target position on CCD1 and affects a significant fraction of the on-axis source PSF (though the effects can be mitigated by suitable on-board offsetting of the signal from that column). We report on our investigations looking for possible pinholes in the XMM-Newton EPIC MOS1 filter created by micro-meteoroid generated debris. New simulation code allows modelling of pinhole patterns in real data sets. We will show the comparison between simulations and specially performed in-orbit detection measurements. These allow us to define the limiting size above which pinholes can be detected and to show if XMM-Newton's filters have suffered significantly from the micro-meteoroids.

The relevance of pre-flight calibration of space-born instruments is widely recognized. As an energy region of interest shifts to hard X-rays in these years, measurement setup becomes difficult to be afforded or maintained by a laboratory- or small-collaboration-based resources. In 10 to 100 KeV region X-ray source that is bright and monochromatic enough to calibrate optics in detail is no longer available other than at synchrotron facilities. Focal length becomes longer and this is another aspect that is beyond capabilities of soft-X-ray-oriented facilities. The hard X-ray instruments for balloon program have been characterized at synchrotron facility SPring-8/BL20B2 in Japan. SPring-8 is one of the world's brightest third generation synchrotron radiation facilities. BL20B2 is specialized for medical and imaging experiment, and has 200m-long transport tube. Measurement at BL20B2 has great advantages such as extremely high flux, large sized and less divergent beam, and monochromatic beam covering entire hard X-ray region from 8 to 12keV. 16m-long experiment hutch is capable of long focal length of hard-X-ray telescope. Pt/C multilayer-supermirror hard X-ray telescopes, position-sensitive scintillation counter and scintillator-deposited CCD, have been characterized at the facility. Insttrumentation of the facility and some of measurement results are presented.

Monitor of All-sky X-ray Image (MAXI) is an X-ray all-sky scanner, which will be attached on Exposed Facility of Japanese Experiment Module dubbed "Kibo" of International Space Station (ISS). MAXI will be launched by the Space Shuttle or the Japanese H-IIA Transfer Vehicle (HTV) in 2008. MAXI carries two types of X-ray cameras: Solid-state Slit Camera (SSC) for 0.5-10 keV and Gas Slit Camera (GSC) for 2-30 keV bands. Both have long narrow fields of view (FOV) made by a slit and orthogonally arranged collimator plates (slats). The FOV will sweep almost the whole sky once every 96 minutes by utilizing the orbital motion of ISS. Then the light curve of an X-ray point source become triangular shape in one transit. In this paper, we present the actual triangular response of the GSC collimator, obtained by our calibration. In fact they are deformed by gaps between the slats, leaning angle of the slats, and the effective width of the slats. We are measuring these sizes by shooting X-ray beams into the detector behind the collimator. We summarize the calibration and present the first compilation of the data to make the GSC collimator response, which will be useful for public users.

The NeXT (New X-ray Telescope) satellite to be launched around 2010, has a large effective area in the 0.1-80 keV band with the use of the multilayer super mirror (HXT). As one of the focal plane detectors for NeXT, we have been developing the Soft X-ray Imager (SXI). SXI consists of charge coupled devices (CCDs). In order to increase the quantum efficiency (Q.E.) as high as possible, i.e., to detect X-rays collected by HXT as many as possible, we developed a "fully-depleted and back-illuminated CCD" in the attempt to improve the Q.E. of soft X-rays by the back-illuminated structure and that of hard X-rays by thickening of a depletion layer. Thanks to a high-resistivity (over 10kΩ•cm) n-type Si, we have successfully developed Pch CCDs with very thick depletion layer of over 300 micron, which is 4 times thicker than that of established X-ray MOS CCDs (for example XIS, EPIC-MOS and ACIS-I). Furthermore, we have already confirmed we can thin a wafer down to 150 micron independent of its resistivity from the experience of the development of the back supportless CCD. Based on these successful results, we fabricated a test device of "fully depleted and back-illuminated CCD" with the high resistivity (10kOhm cm) N-type Si thinned down to 200 micron. The pixel number and size are 512 x 512 and 24 x 24 μm, respectively. For optical blocking, we coated the surface with Al. We evaluated this test device and confirmed the thickness of depletion layer reaches 200 micron as we expected. In this paper, we present progress in development of these devices for SXI.

We have produced various gas electron multiplier foils (GEMs) by using laser etching technique for cosmic X-ray polarimeters. The finest structure GEM we have fabricated has 30 μm-diameter holes on a 50 μm-pitch. The effective gain of the GEM reaches around 5000 at the voltage of 570 V between electrodes. The gain is slightly higher than that of the CERN standard GEM with 70 μm-diameter holes on a 140 μm-pitch. We have fabricated GEMs with thickness of 100 μm which has two times thicker than the standard GEM. The effective gain of the thick-foil GEM is 104 at the applied voltage of 350 V per 50 μm of thickness. The gain is about two orders higher than that of the standard GEM. The remarkable characteristic of the thick-foil GEM is that the effective gain at the beginning of micro-discharge is quite improved. For fabricating the thick-foil GEMs, we have employed new material, liquid crystal polymer (LCP) which has little moisture absorption rate, as an insulator layer instead of polyimide. One of the thick-foil GEM we have fabricated has 8 μm copper layer in the middle of the 100 μm-thick insulator layer. The metal layer in the middle of the foil works as a field-shaper in the multiplication channels, though it slightly decreases the effective gain.

We present a performance study of a cosmic X-ray polarimeter which is based on the photoelectric effect in gas, and sensitive to a few to 30 keV range. In our polarimeter, the key device would be the 50 μm pitch Gas Electron Multiplier (GEM). We have evaluated the modulation factor using highly polarized X-ray, provided by a synchrotron accelerator. In the analysis, we selected events by the eccentricity of the charge cloud of the photoelectron track. As a result, we obtained the relationship between the selection criteria for the eccentricity and the modulation factors; for example, when we selected the events which have their eccentricity of > 0.95, the polarimeter exhibited with the modulation factor of 0.32. In addition, we estimated the Minimum Detectable Polarization degree (MDP) of Crab Nebula with our polarimeter and found 10 ksec observation is enough to detect the polarization, if we adopt suitable X-ray mirrors.

We report on a large active area (15x15mm2), high channel density (470 pixels/mm2), self-triggering CMOS analog chip that we have developed as pixelized charge collecting electrode of a Micropattern Gas Detector. This device, which represents a big step forward both in terms of size and performance, is the last version of three generations of custom ASICs of increasing complexity. The CMOS pixel array has the top metal layer patterned in a matrix of 105600 hexagonal pixels at 50μm pitch. Each pixel is directly connected to the underneath full electronics chain which has been realized in the remaining five metal and single poly-silicon layers of a standard 0.18μm CMOS VLSI technology. The chip has customizable self-triggering capability and includes a signal pre-processing function for the automatic localization of the event coordinates. In this way it is possible to reduce significantly the readout time and the data volume by limiting the signal output only to those pixels belonging to the region of interest. The very small pixel area and the use of a deep sub-micron CMOS technology has brought the noise down to 50 electrons ENC. Results from in depth tests of this device when coupled to a fine pitch (50μm on a triangular pattern) Gas Electron Multiplier are presented. The matching of readout and gas amplification pitch allows getting optimal results. The application of this detector for Astronomical X-Ray Polarimetry is discussed. The experimental detector response to polarized and unpolarized X-ray radiation when working with two gas mixtures and two different photon energies is shown. Results from a full MonteCarlo simulation for several galactic and extragalactic astronomical sources are also reported.

XEUS is a large area telescope aiming to rise X-ray Astronomy to the level of Optical Astronomy in terms of collecting areas. It will be based on two satellites, locked on a formation flight, one with the optics, one with the focal plane. The present design of the focal plane foresees, as an auxiliary instrument, the inclusion of a Polarimeter based on a Micropattern Chamber. We show how such a device is capable to solve open problems on many classes of High Energy Astrophysics objects and to use X-ray sources as a laboratory for a substantial progress on Fundamental Physics.

The X-ray Imaging Spectrometer on the Suzaku satellite consists three front-illuminated (FI) and one back-illuminated (BI) CCD cameras. Using ground calibration data taken at Kyoto University and Osaka University, we obtained the energy response of the XIS, which consists of at least six components: 1. a main peak, 2. a sub peak, 3. a triangle component, 4. a Si escape, 5. a Si line, and 6. a constant component. The relation between the energy and the pulse height was also estimated, which is called as a gain. The relation cannot be represented with a single linear function. Then we divided the gain into two parts at the Si edge (1.839 keV) and each part can be described with a single linear function. Thus there is a discontinuity at 1.839 keV in the XIS gain. We have monitored the variation of the gain and energy resolution in orbit by observing the calibration source of 55Fe illuminating two corners of each CCD.

Suzaku is the fifth Japanese X-ray astronomical satellite and it was launched in July 2005. The Suzaku X-ray Imaging Spectrometers (XISs) consist of four X-ray Charge-Coupled Device (CCD) cameras. Three of them are front-illuminated (FI) CCD, and the other is back-illuminated (BI) CCD. The strong points of the XIS are a high energy resolution, a large effective area, and a low and stable background. In particular, the background level of the Suzaku/XIS is much lower than the other X-ray satellites, XMM-Newton/EPIC and Chandra/ACIS. We investigated the background property of the XIS using the data obtained when the satellite is looking at the night earth, and proved the low level and the stability of the XIS background. Non X-ray background (NXB) consists of continuum component and some emission lines. The continuum component is very different between the FI-CCD and the BI-CCD. We discussed the positional dependence of the continuum component and the line components, and proved that the flux of the line components of the NXB is higher in the frame-store region than the imaging area. Finally, we investigated the effects of magnetic cut-off rigidity (COR) upon the count rate of NXB.

The X-ray astronomical satellite Suzaku was successfully launched in July 2005. The onboard Wideband All-sky Monitor (WAM) is designed as the second function of the large, thick BGO anti-coincidence shields of the Hard X-ray Detectors (HXD). It views about half of the whole sky and has a geometrical area of 800 cm² per side, with a large effective area of 400 cm² even at 1 MeV. Hence, the WAM is expected to provide unique opportunities to detect high energy emission from GRBs and solar flares in the MeV range. In fact, the WAM has detected at least 47 GRBs, although the fine-tuning of the GRB functions is still in progress. The most impressive GRB result is the bright, hard spectrum GRB 051008, which was detected up to 1 MeV with the WAM. We will present here the in-flight performance of the HXD/WAM during the initial eight-months of operations. The in-flight energy response, spectral and timing capabilities, and in-orbit background are described in this paper.

We present a new sounding rocket payload that will perform high resolution (R~100) x-ray spectroscopy of diffuse celestial x-ray sources. The instrument features a new geometry that allows for high resolution along with high throughput. A wire grid collimator constrains light from diffuse sources into a converging beam that feeds an array of diffraction gratings in the extreme off-plane mount. Starting with launch in 2006 we can obtain physical diagnostics of supernova remnants such as the Cygnus Loop and ultimately the hot phase of the interstellar medium.